System and method of handling bandwidth part inactivity timer

ABSTRACT

The present disclosure relates to a communication method and system for converging a 5th-Generation (5G) communication system for supporting higher data rates beyond a 4th-Generation (4G) system with a technology for Internet of Things (IoT). The present disclosure may be applied to intelligent services based on the 5G communication technology and the IoT-related technology, such as smart home, smart building, smart city, smart car, connected car, health care, digital education, smart retail, security and safety services. A method of a UE is provided. The method includes receiving first information of a timer associated with a beam failure recovery and second information of maximum count value associated with beam failure instance; identifying a number of beam failure instances; identifying whether the number of beam failure instances is greater or equal to the second information; starting the timer associated with the beam failure recovery in response to identifying that the number of beam failure instances is greater or equal to the second information; transmitting a contention-free random access preamble for initiating a random access procedure for a beam failure recovery request; receiving physical downlink control channel (PDCCH) associated with a cell radio network temporary identifier (C-RNTI) of the UE; identifying whether the random access procedure is completed successfully; and stopping the timer in response to identifying that the random access procedure is completed successfully.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is based on and claims priority under 35 U.S.C. § 119of a U.S. Provisional application Ser. No. 62/608,911, filed on Dec. 21,2017, in the U.S. Patent and Trademark Office, the disclosure of whichis incorporated by reference herein in its entirety.

BACKGROUND 1. Field

The disclosure relates to a wireless communication system. Moreparticularly, the disclosure relates to a method and apparatus forhandling bandwidth part inactivity timer. More particularly, thedisclosure relates to a method and apparatus for a random accessprocedure initiated for requesting system information. Moreparticularly, the disclosure relates to a method and apparatus forbandwidth part (BWP) switching. More particularly, the disclosurerelates to a method and apparatus for a random access procedureinitiated for a beam failure recovery.

2. Description of Related Art

To meet the demand for wireless data traffic having increased sincedeployment of 4G communication systems, efforts have been made todevelop an improved 5G or pre-5G communication system. Therefore, the 5Gor pre-5G communication system is also called a ‘Beyond 4G Network’ or a‘Post LTE System’. In 5G communication systems, development for systemnetwork improvement is under way based on advanced small cells, cloudradio access networks (RANs), ultra-dense networks, device-to-device(D2D) communication, wireless backhaul, moving network, cooperativecommunication, coordinated multi-points (CoMP), reception-endinterference cancellation and the like. In the 5G system, hybrid FSK andQAM modulation (FQAM) and sliding window superposition coding (SWSC) asan advanced coding modulation (ACM), and filter bank multi carrier(FBMC), non-orthogonal multiple access (NOMA), and sparse code multipleaccess (SCMA) as an advanced access technology have been developed.

The Internet, which is a human centered connectivity network wherehumans generate and consume information, is now evolving to the internetof things (IoT) where distributed entities, such as things, exchange andprocess information without human intervention. The internet ofeverything (IoE), which is a combination of the IoT technology and theBig Data processing technology through connection with a cloud server,has emerged. As technology elements, such as “sensing technology”,“wired/wireless communication and network infrastructure”, “serviceinterface technology”, and “Security technology” have been demanded forIoT implementation, a sensor network, a machine-to-machine (M2M)communication, machine type communication (MTC), and so forth have beenrecently researched. Such an IoT environment may provide intelligentInternet technology services that create a new value to human life bycollecting and analyzing data generated among connected things. IoT maybe applied to a variety of fields including smart home, smart building,smart city, smart car or connected cars, smart grid, health care, smartappliances and advanced medical services through convergence andcombination between existing information technology (IT) and variousindustrial applications.

In line with this, various attempts have been made to apply 5Gcommunication systems to IoT networks. For example, technologies such asa sensor network, machine type communication (MTC), andmachine-to-machine (M2M) communication may be implemented bybeamforming, multiple-input multiple-output (MIMO), and array antennas.Application of a cloud Radio Access Network (RAN) as the above-describedBig Data processing technology may also be considered to be as anexample of convergence between the 5G technology and the IoT technology.

The above information is presented as background information only toassist with an understanding of the disclosure. No determination hasbeen made, and no assertion is made, as to whether any of the abovemight be applicable as prior art with regard to the disclosure.

SUMMARY

Aspects of the disclosure are to address at least the above-mentionedproblems and/or disadvantages and to provide at least the advantagesdescribed below.

Additional aspects will be set forth in part in the description whichfollows and, in part, will be apparent from the description, or may belearned by practice of the presented embodiments.

In accordance with an aspect of the disclosure, a method of a userequipment (UE) in a wireless communication system is provided. Themethod includes receiving, from a base station, first information of afirst timer of a bandwidth part inactivity associated with a bandwidthpart of a primary cell (PCell) and second information of a second timerof a bandwidth part inactivity associated with a bandwidth part of asecondary cell (SCell); identifying that a random access procedure isinitiated on the PCell or the SCell; stopping the first timer, ifrunning, in response to identifying that the random access procedure isinitiated on the PCell; and stopping the first timer and the secondtimer, if running, in response to identifying that the random accessprocedure is initiated on the SCell.

The SCell and the PCell are associated with the random access procedure.

The random access procedure is performed based on an active uplink (UL)bandwidth part (BWP) of the PCell or the SCell.

The random access procedure is performed based on an active downlink(DL) bandwidth part (BWP) of the PCell.

In accordance with an aspect of the disclosure, a method of a basestation is provided. The method includes transmitting, to a userequipment (UE), first information of a first timer of a bandwidth partinactivity associated with a bandwidth part of a primary cell (PCell)and second information of a second timer of a bandwidth part inactivityassociated with a bandwidth part of a secondary cell (SCell); receiving,from the UE, a first message associated with a random access procedureon the PCell or the SCell; and transmitting, to the UE, a second messageassociated with the random access procedure on the PCell, wherein thefirst timer, if running, is stopped in response to identifying that therandom access procedure is initiated on the PCell, and wherein the firsttimer and the second timer, if running, are stopped in response toidentifying that the random access procedure is initiated on the SCell.′

The SCell and the PCell are associated with the random access procedure.

The first message including physical random access channel (PRACH)preamble is received on an active uplink (UL) bandwidth part (BWP) ofthe PCell or the SCell.

The second message including random access response (RAR) is transmittedon an active downlink (DL) bandwidth part (BWP) of the PCell.

In accordance with an aspect of the disclosure, a UE in a wirelesscommunication system is provided. The UE includes a transceiver; and atleast one processor coupled to the transceiver, the processor configuredto: control the transceiver to receive, from a base station, firstinformation of a first timer of a bandwidth part inactivity associatedwith a bandwidth part of a primary cell (PCell) and second informationof a second timer of a bandwidth part inactivity associated with abandwidth part of a secondary cell (SCell); identify that a randomaccess procedure is initiated on the PCell or the SCell; stop the firsttimer, if running, in response to identifying that the random accessprocedure is initiated on the PCell; and stop the first timer and thesecond timer, if running, in response to identifying that the randomaccess procedure is initiated on the SCell.

The SCell and the PCell are associated with the random access procedure.

The random access procedure is performed based on an active uplink(UL)bandwidth part (BWP) of the PCell or the SCell.

The random access procedure is performed based on an active downlink(DL) bandwidth part (BWP) of the PCell.

In accordance with an aspect of the present disclosure, a base stationin a wireless communication system is provided. The base stationincludes a transceiver; and at least one processor coupled to thetransceiver, the processor configured to control the transceiver to:transmit, to a user equipment (UE), first information of a first timerof a bandwidth part inactivity associated with a bandwidth part of aprimary cell (PCell) and second information of a second timer of abandwidth part inactivity associated with a bandwidth part of asecondary cell (SCell); receive, from the UE, a first message associatedwith a random access procedure on the PCell or the SCell; and transmit,to the UE, a second message associated with the random access procedureon the PCell, wherein the first timer, if running, is stopped inresponse to identifying that the random access procedure is initiated onthe PCell, and wherein the first timer and the second timer, if running,are stopped in response to identifying that the random access procedureis initiated on the SCell.

The first message including physical random access channel (PRACH)preamble is received on an active uplink (UL) bandwidth part (BWP) ofthe PCell or the SCell.

The second message including random access response (RAR) is transmittedon an active downlink (DL) bandwidth part (BWP) of the PCell.

In accordance with an aspect of the disclosure, a method of a userequipment (UE) in a wireless communication system is provided. Themethod includes receiving, from a base station, first information of atimer associated with bandwidth part (BWP) inactivity; receiving, fromthe base station, physical downlink control channel (PDCCH) on an activeBWP associated with a serving cell; identifying whether there is ongoingrandom access procedure associated with the serving cell; and startingor re-starting the timer in response to identifying that there is noongoing random access procedure associated with the serving cell.

The active BWP is different from either a default downlink (DL)bandwidth part (BWP) or an initial BWP.

The PDCCH indicates a downlink assignment or an uplink grant.

The PDCCH is received on the active BWP or received for the active BWP.

In accordance with an aspect of the disclosure, a method of a basestation is provided. The method includes transmitting, to a userequipment(UE), first information of a timer associated with bandwidthpart (BWP) inactivity; and transmitting, to the UE, physical downlinkcontrol channel (PDCCH) on an active BWP associated with a serving cell,wherein the timer is started or re-started in response to identifyingthat there is no ongoing random access procedure associated with theserving cell.

The active BWP is different from either a default downlink (DL)bandwidth part (BWP) or an initial BWP.

The PDCCH indicates a downlink assignment or an uplink grant.

The PDCCH is transmitted on the active BWP or transmitted for the activeBWP.

In accordance with an aspect of the disclosure, a UE in a wirelesscommunication system is provided. The UE includes a transceiver; and atleast one processor coupled to the transceiver, the processor configuredto: receive, from a base station, first information of a timerassociated with bandwidth part (BWP) inactivity; receive, from the basestation, physical downlink control channel (PDCCH) on an active BWPassociated with a serving cell; identify whether there is ongoing randomaccess procedure associated with the serving cell; and start or re-startthe timer in response to identifying that there is no ongoing randomaccess procedure associated with the serving cell.

The active BWP is different from either a default downlink (DL)bandwidth part (BWP) or an initial BWP.

The PDCCH indicates a downlink assignment or an uplink grant.

The PDCCH is received on the active BWP or received for the active BWP.

In accordance with an aspect of the present disclosure, a base stationin a wireless communication system is provided. The base stationincludes a transceiver; and at least one processor coupled to thetransceiver, the processor configured to control the transceiver to:transmit, to a user equipment(UE), first information of a timerassociated with bandwidth part (BWP) inactivity; and transmit, to theUE, physical downlink control channel (PDCCH) on an active BWPassociated with a serving cell, wherein the timer is started orre-started in response to identifying that there is no ongoing randomaccess procedure associated with the serving cell.

The PDCCH indicates a downlink assignment or an uplink grant.

The PDCCH is transmitted on the active BWP or transmitted for the activeBWP.

In accordance with an aspect of the disclosure, a method of a userequipment (UE) in a wireless communication system is provided. Themethod includes transmitting, to a base station, a random accesspreamble for initiating a random access procedure; receiving, from thebase station, a random access response; transmitting, to the basestation, a first message for requesting system information (SI);receiving, from the base station, physical downlink control channel(PDCCH) associated with a temporary cell radio network temporaryidentifier (TEMPORARY C-RNTI); identifying whether a contentionresolution is successful; identifying whether a random access procedureis initiated for requesting the SI; and indicating a reception of anacknowledgement for requesting the SI to upper layer in response toidentifying that the contention resolution is successful and the randomaccess procedure is initiated for requesting the SI.

A cell radio network temporary identifier (C-RNTI) is set to a value ofthe TEMPORARY C-RNTI in response to identifying that the contentionresolution is successful and the random access procedure is notinitiated for requesting the SI.

The random access procedure is associated with contention-based randomaccess.

A contention resolution is identified successful in response toidentifying that UE Contention Resolution Identity in a MAC CE receivedin a MAC PDU matches a CCCH SDU transmitted in the first message

In accordance with an aspect of the disclosure, a method of a basestation is provided. The method includes receiving, from a userequipment (UE), a random access preamble for initiating a random accessprocedure; transmitting, to the UE, a random access response; receiving,from the UE, a first message for requesting system information (SI);transmitting, to the UE, physical downlink control channel (PDCCH)associated with a temporary cell radio network temporary identifier(TEMPORARY C-RNTI); and transmitting, to the UE, an acknowledgement forrequesting the SI in response to identifying that a contentionresolution is successful and a random access procedure is initiated forrequesting the SI.

A cell radio network temporary identifier (C-RNTI) is set to a value ofthe TEMPORARY C-RNTI in response to identifying that the contentionresolution is successful and the random access procedure is notinitiated for requesting the SI.

The random access procedure is associated with contention-based randomaccess.

A contention resolution is identified successful in response toidentifying that UE Contention Resolution Identity in a MAC CEtransmitted in a MAC PDU matches a CCCH SDU received in the firstmessage.

In accordance with an aspect of the disclosure, a UE in a wirelesscommunication system is provided. The UE includes a transceiver; and atleast one processor coupled to the transceiver, the processor configuredto control the transceiver to transmit, to a base station, a randomaccess preamble for initiating a random access procedure and receive,from the base station, a random access response and transmit, to thebase station, a first message for requesting system information (SI) andreceive, from the base station, physical downlink control channel(PDCCH) associated with a temporary cell radio network temporaryidentifier (TEMPORARY C-RNTI); identify whether a contention resolutionis successful; identify whether a random access procedure is initiatedfor requesting the SI; and indicate a reception of an acknowledgementfor requesting the SI to upper layer in response to identifying that thecontention resolution is successful and the random access procedure isinitiated for requesting the SI.

The processor is further configured to set cell radio network temporaryidentifier (C-RNTI) to a value of the TEMPORARY C-RNTI in response toidentifying that the contention resolution is successful and the randomaccess procedure is not initiated for requesting the SI.

The random access procedure is associated with contention-based randomaccess.

A contention resolution is identified successful in response toidentifying that UE Contention Resolution Identity in a MAC CE receivedin a MAC PDU matches a CCCH SDU transmitted in the first message.

In accordance with an aspect of the present disclosure, a base stationin a wireless communication system is provided. The base stationincludes a transceiver; and at least one processor coupled to thetransceiver, the processor configured to control the transceiver toreceive, from a user equipment (UE), a random access preamble forinitiating a random access procedure and transmit, to the UE, a randomaccess response and receive, from the UE, a first message for requestingsystem information (SI) and transmit, to the UE, physical downlinkcontrol channel (PDCCH) associated with a temporary cell radio networktemporary identifier (TEMPORARY C-RNTI) and transmit, to the UE, anacknowledgement for requesting the SI in response to identifying that acontention resolution is successful and a random access procedure isinitiated for requesting the SI.

A cell radio network temporary identifier (C-RNTI) is set to a value ofthe TEMPORARY C-RNTI in response to identifying that the contentionresolution is successful and the random access procedure is notinitiated for requesting the SI.

A contention resolution is identified successful in response toidentifying that UE Contention Resolution Identity in a MAC CEtransmitted in a MAC PDU matches a CCCH SDU received in the firstmessage.

In accordance with an aspect of the disclosure, a method of a userequipment (UE) in a wireless communication system is provided. Themethod includes receiving, from a base station, physical downlinkcontrol channel (PDCCH) for bandwidth part (BWP) switching of a servingcell; identifying whether there is ongoing random access procedureassociated with the serving cell; and performing BWP switching based onthe PDCCH in response to identifying that there is no ongoing randomaccess procedure.

The BWP switching is performed based on the PDCCH in response toidentifying that there is ongoing random access procedure.

The ongoing random access procedure is stopped in response toidentifying that the BWP switching is performed.

The PDCCH for BWP switching is ignored in response to identifying thatthere is ongoing random access procedure.

In accordance with an aspect of the disclosure, a method of a basestation is provided. The method includes transmitting, to a userequipment(UE), bandwidth part (BWP) configuration information includinginformation associated with an active bandwidth part (BWP) of a servingcell; and transmitting, to the UE, physical downlink control channel(PDCCH) for bandwidth part (BWP) switching of the serving cell, whereinthe BWP switching is performed based on the PDCCH in response toidentifying that there is no ongoing random access procedure associatedwith the serving cell.

The BWP switching is performed based on the PDCCH in response toidentifying that there is ongoing random access procedure associatedwith the serving cell.

The ongoing random access procedure is stopped in response toidentifying that the BWP switching is performed.

The PDCCH for BWP switching is ignored in response to identifying thatthere is ongoing random access procedure associated with the servingcell.

In accordance with an aspect of the disclosure, a UE in a wirelesscommunication system is provided. The UE includes a transceiver; and atleast one processor coupled to the transceiver, the processor configuredto: control the transceiver to receive, from a base station, physicaldownlink control channel (PDCCH) for bandwidth part (BWP) switching of aserving cell; identify whether there is ongoing random access procedureassociated with the serving cell; and perform BWP switching based on thePDCCH in response to identifying that there is no ongoing random accessprocedure.

The BWP switching is performed based on the PDCCH in response toidentifying that there is ongoing random access procedure.

The ongoing random access procedure is stopped in response toidentifying that the BWP switching is performed.

The PDCCH for BWP switching is ignored in response to identifying thatthere is ongoing random access procedure.

In accordance with an aspect of the present disclosure, a base stationin a wireless communication system is provided. The base stationincludes a transceiver; and at least one processor coupled to thetransceiver, the processor configured to control the transceiver to:transmit, to a user equipment(UE), bandwidth part (BWP) configurationinformation including information associated with an active bandwidthpart (BWP) of a serving cell; and transmit, to the UE, physical downlinkcontrol channel (PDCCH) for bandwidth part (BWP) switching of theserving cell, wherein the BWP switching is performed based on the PDCCHin response to identifying that there is no ongoing random accessprocedure associated with the serving cell.

The BWP switching is performed based on the PDCCH in response toidentifying that there is ongoing random access procedure associatedwith the serving cell.

The DCI for the BWP switching is ignored in response to identifying thatthere is ongoing random access procedure associated with the servingcell.

In accordance with an aspect of the disclosure, a method of a userequipment (UE) in a wireless communication system is provided. Themethod includes receiving first information of a timer associated with abeam failure recovery and second information of maximum count valueassociated with beam failure instance; identifying a number of beamfailure instances; identifying whether the number of beam failureinstances is greater or equal to the second information; starting thetimer associated with the beam failure recovery in response toidentifying that the number of beam failure instances is greater orequal to the second information; transmitting a contention-free randomaccess preamble for initiating a random access procedure for a beamfailure recovery request; receiving physical downlink control channel(PDCCH) associated with a cell radio network temporary identifier(C-RNTI) of the UE; identifying whether the random access procedure iscompleted successfully; and stopping the timer in response toidentifying that the random access procedure is completed successfully.

The first information and the second information is received by higherlayer signaling.

The number of beam failure instances is set to zero in response toidentifying that the random access procedure is completed successfully.

The beam failure recovery is identified completed in response toidentifying that the random access procedure is completed successfully.

In accordance with an aspect of the disclosure, a method of a basestation is provided. The method includes transmitting, to a userequipment (UE), first information of a timer associated with a beamfailure recovery and second information of maximum count valueassociated with beam failure instance; receiving, from UE, acontention-free random access preamble for initiating a random accessprocedure for a beam failure recovery request; and transmitting, to theUE, physical downlink control channel (PDCCH) associated with a cellradio network temporary identifier (C-RNTI) of the UE, wherein the timeris started in response to identifying that a number of beam failureinstances is greater or equal to the second information and the timer isstopped in response to identifying that the random access procedure iscompleted successfully.

The first information and the second information is transmitted byhigher layer signaling

The number of beam failure instances is set to zero in response toidentifying that the random access procedure is completed successfully.

The beam failure recovery is identified completed in response toidentifying that the random access procedure is completed successfully.

In accordance with an aspect of the disclosure, a UE in a wirelesscommunication system is provided. The UE includes a transceiver; and atleast one processor coupled to the transceiver, the processor configuredto: control the transceiver to receive first information of a timerassociated with a beam failure recovery and second information ofmaximum count value associated with beam failure instance; identify anumber of beam failure instances; identify whether the number of beamfailure instances is greater or equal to the second information; startthe timer associated with the beam failure recovery in response toidentifying that the number of beam failure instances is greater orequal to the second information; control the transceiver to transmit acontention-free random access preamble for initiating a random accessprocedure for a beam failure recovery request; control the transceiverto receive physical downlink control channel (PDCCH) associated with acell radio network temporary identifier (C-RNTI) of the UE; identifywhether the random access procedure is completed successfully; and stopthe timer in response to identifying that the random access procedure iscompleted successfully.

The first information and the second information is received by higherlayer signaling.

The number of beam failure instances is set to zero in response toidentifying that the random access procedure is completed successfully.

The beam failure recovery is identified completed in response toidentifying that the random access procedure is completed successfully.

In accordance with an aspect of the present disclosure, a base stationin a wireless communication system is provided. The base stationincludes a transceiver; and at least one processor coupled to thetransceiver, the processor configured to control the transceiver to:transmit, to a user equipment (UE), first information of a timerassociated with a beam failure recovery and second information ofmaximum count value associated with beam failure instance; receive, fromUE, a contention-free random access preamble for initiating a randomaccess procedure for a beam failure recovery request; and transmit, tothe UE, physical downlink control channel (PDCCH) associated with a cellradio network temporary identifier (C-RNTI) of the UE, wherein the timeris started in response to identifying that a number of beam failureinstances is greater or equal to the second information and the timer isstopped in response to identifying that the random access procedure iscompleted successfully.

The number of beam failure instances is set to zero in response toidentifying that the random access procedure is completed successfully.

The beam failure recovery is identified completed in response toidentifying that the random access procedure is completed successfully.

Other aspects, advantages, and salient features of the disclosure willbecome apparent to those skilled in the art from the following detaileddescription, which, taken in conjunction with the annexed drawings,discloses various embodiments of the disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features, and advantages of certainembodiments of the disclosure will be more apparent from the followingdescription taken in conjunction with the accompanying drawings, inwhich:

FIG. 1 illustrates an operation of the BWP-InactivityTimer associatedwith the random access procedure according to an embodiment of thedisclosure;

FIG. 2 illustrates UE operation in one embodiment of the proposedinvention to handle BWP-InactivityTimer when UE is configured withmultiple serving cells and random access procedure is initiatedaccording to an embodiment of the disclosure;

FIG. 3 illustrates UE operation in another embodiment of the proposedinvention to handle BWP-InactivityTimer when UE is configured withmultiple serving cells and random access procedure is initiatedaccording to an embodiment of the disclosure;

FIG. 4 illustrates UE operation in another embodiment of the proposedinvention to handle BWP-InactivityTimer when UE is configured withmultiple serving cells and random access procedure is initiatedaccording to an embodiment of the disclosure;

FIG. 5 illustrates UE operation in another embodiment of the proposeddisclosure to handle BWP-InactivityTimer when UE is configured withmultiple serving cells and random access procedure is initiatedaccording to an embodiment of the disclosure;

FIG. 6 illustrates UE operation in one embodiment of the proposedinvention to handle BWP-InactivityTimer when UE is configured withmultiple serving cells and random access procedure is completedaccording to an embodiment of the disclosure;

FIG. 7 illustrates UE operation in another embodiment of the proposedinvention to handle BWP-InactivityTimer when UE is configured withmultiple serving cells and random access procedure is completedaccording to an embodiment of the disclosure;

FIG. 8 illustrates UE operation in another embodiment of the proposedinvention to handle BWP-InactivityTimer when UE is configured withmultiple serving cells and random access procedure is completedaccording to an embodiment of the disclosure;

FIG. 9 illustrates UE operation in another embodiment of the proposedinvention to handle BWP-InactivityTimer when UE is configured withmultiple serving cells and random access procedure is completedaccording to an embodiment of the disclosure;

FIG. 10 illustrates UE operation in one embodiment of the proposedinvention to handle BWP-InactivityTimer when PDCCH with DL Assignment isreceived on or for the active DL BWP according to an embodiment of thedisclosure;

FIG. 11 illustrates UE operation in one embodiment of the proposedinvention to handle BWP-InactivityTimer when PDCCH with UL Grant isreceived on or for the active BWP according to an embodiment of thedisclosure;

FIG. 12 illustrates UE operation in one embodiment of the proposedinvention to handle measurement gap during Beam Failure RecoveryResponse Window according to an embodiment of the disclosure;

FIG. 13 illustrates a UE apparatus according to an embodiment to thedisclosure; and

FIG. 14 illustrates a base station apparatus according to an embodimentof the disclosure.

Throughout the drawings, it should be noted that like reference numbersare used to depict the same or similar elements, features, andstructures.

DETAILED DESCRIPTION

The following description with reference to the accompanying drawings isprovided to assist in a comprehensive understanding of variousembodiments of the disclosure as defined by the claims and theirequivalents. It includes various specific details to assist in thatunderstanding but these are to be regarded as merely exemplary.Accordingly, those of ordinary skill in the art will recognize thatvarious changes and modifications of the various embodiments describedherein can be made without departing from the scope and spirit of thedisclosure. In addition, descriptions of well-known functions andconstructions are omitted for clarity and conciseness

The terms and words used in the following description and claims are notlimited to the bibliographical meanings, but, are merely used by theinventor to enable a clear and consistent understanding of thedisclosure. Accordingly, it should be apparent to those skilled in theart that the following description of various embodiments of thedisclosure is provided for illustration purpose only and not for thepurpose of limiting the disclosure as defined by the appended claims andtheir equivalents.

It is to be understood that the singular forms “a,” “an,” and “the”include plural referents unless the context clearly dictates otherwise.Thus, for example, reference to “a component surface” includes referenceto one or more of such surfaces.

In each drawing, the same or similar components may be denoted by thesame reference numerals.

Each block of the flow charts and combinations of the flow charts may beperformed by computer program instructions. Because these computerprogram instructions may be mounted in processors for a generalcomputer, a special computer, or other programmable data processingapparatuses, these instructions executed by the processors for thecomputer or the other programmable data processing apparatuses createmeans performing functions described in block(s) of the flow charts.Because these computer program instructions may also be stored in acomputer usable or computer readable memory of a computer or otherprogrammable data processing apparatuses in order to implement thefunctions in a specific scheme, the computer program instructions storedin the computer usable or computer readable memory may also producemanufacturing articles including instruction means performing thefunctions described in block(s) of the flow charts. Because the computerprogram instructions may also be mounted on the computer or the otherprogrammable data processing apparatuses, the instructions performing aseries of operation steps on the computer or the other programmable dataprocessing apparatuses to create processes executed by the computer tothereby execute the computer or the other programmable data processingapparatuses may also provide steps for performing the functionsdescribed in block(s) of the flow charts.

In addition, each block may indicate a module, a segment, and/or a codeincluding one or more executable instructions for executing a specificlogical function(s). Further, functions mentioned in the blocks occurregardless of a sequence in some alternative embodiments. For example,two blocks that are consecutively illustrated may be simultaneouslyperformed in fact or be performed in a reverse sequence depending oncorresponding functions sometimes.

Herein, the term “unit” may include software and/or hardware components,such as a field-programmable gate array (FPGA) and/or anapplication-specific integrated circuit (ASIC). However, the meaning of“unit” is not limited to software and/or hardware. For example, a unitmay be configured to be in a storage medium that may be addressed andmay also be configured to reproduce one or more processor. Accordingly,a “unit” may include components such as software components, objectoriented software components, class components, task components,processors, functions, attributes, procedures, subroutines, segments ofprogram code, drivers, firmware, microcode, circuit, data, database,data structures, tables, arrays, and variables.

Functions provided in the components and the “units” may be combinedwith a smaller number of components and/or “units” or may furtherseparated into additional components and/or “units”.

In addition, components and units may also be implemented to reproduceone or more CPUs within a device or a security multimedia card.

The terms as used in the disclosure are provided to describe specificembodiments, and do not limit the scope of other embodiments. It is tobe understood that singular forms include plural forms unless thecontext clearly dictates otherwise. Unless otherwise defined, the termsand words including technical or scientific terms used in the followingdescription and claims may have the same meanings as generallyunderstood by those skilled in the art. The terms as generally definedin dictionaries may be interpreted as having the same or similarmeanings as the contextual meanings of related technology. Unlessotherwise defined, the terms should not be interpreted as ideally orexcessively formal meanings. When needed, even the terms as defined inthe disclosure may not be interpreted as excluding embodiments of thedisclosure.

Herein, a base station performs resource allocation to a terminal.Examples of the base station may include an eNode B, a Node B, awireless access unit, a base station controller, a node on a network,etc. Examples of the terminal may include a user equipment (UE), amobile station (MS), a cellular phone, a smart phone, a computer, amultimedia system performing a communication function, etc.

Herein, a downlink (DL) is a radio transmission path of a signal from abase station to a UE and an uplink (UL) is a radio transmission path ofa signal from the UE to the base station.

The embodiments of the disclosure may be applied to other communicationsystems having similar technical backgrounds or channel forms.

In the recent years several broadband wireless technologies have beendeveloped to meet the growing number of broadband subscribers and toprovide more and better applications and services. The second generationwireless communication system has been developed to provide voiceservices while ensuring the mobility of users. Third generation wirelesscommunication system supports not only the voice service but also dataservice. In recent years, the fourth wireless communication system hasbeen developed to provide high-speed data service. However, currently,the fourth generation wireless communication system suffers from lack ofresources to meet the growing demand for high speed data services. So,the fifth generation wireless communication system is being developed tomeet the growing demand for high speed data services, supportultra-reliability and low latency applications.

The fifth generation wireless communication system will be implementednot only in lower frequency bands but also in higher frequency (mmWave)bands, e.g., 10 GHz to 100 GHz bands, so as to accomplish higher datarates. To mitigate propagation loss of the radio waves and increase thetransmission distance, the beamforming, massive Multiple-InputMultiple-Output (MIMO), Full Dimensional MIMO (FD-MIMO), array antenna,an analog beam forming, large scale antenna techniques are beingconsidered in the design of fifth generation wireless communicationsystem. In addition, the fifth generation wireless communication systemis expected to address different use cases having quite differentrequirements in terms of data rate, latency, reliability, mobility etc.However, it is expected that the design of the air-interface of thefifth generation wireless communication system would be flexible enoughto serve the UEs having quite different capabilities depending on theuse case and market segment the UE cater service to the end customer.Few examples use cases the fifth generation wireless communicationsystem wireless system is expected to address is enhanced MobileBroadband (eMBB), massive Machine Type Communication (m-MTC),ultra-reliable low latency communication (URLL) etc. The eMBBrequirements like tens of Gbps data rate, low latency, high mobility soon and so forth address the market segment representing the conventionalwireless broadband subscribers needing internet connectivity everywhere,all the time and on the go. The m-MTC requirements like very highconnection density, infrequent data transmission, very long batterylife, low mobility address so on and so forth address the market segmentrepresenting the Internet of Things (IoT)/Internet of Everything (IoE)envisioning connectivity of billions of devices. The URLL requirementslike very low latency, very high reliability and variable mobility so onand so forth address the market segment representing the Industrialautomation application, vehicle-to-vehicle/vehicle-to-infrastructurecommunication foreseen as one of the enablers for autonomous cars.

The fifth generation wireless communication system (also referred asnext generation radio or NR), supports standalone mode of operation aswell dual connectivity (DC). In DC a multiple Rx/Tx UE may be configuredto utilize resources provided by two different nodes (or NBs) connectedvia non-ideal backhaul. One node acts as the Master Node (MN) and theother as the Secondary Node (SN). The MN and SN are connected via anetwork interface and at least the MN is connected to the core network.NR also supports Multi-RAT Dual Connectivity (MR-DC) operation whereby aUE in RRC_CONNECTED is configured to utilize radio resources provided bytwo distinct schedulers, located in two different nodes connected via anon-ideal backhaul and providing either E-UTRA (i.e. if the node is anng-eNB) or NR access (i.e. if the node is a gNB).

In NR for a UE in RRC_CONNECTED not configured with CA/DC there is onlyone serving cell comprising of the primary cell. For a UE inRRC_CONNECTED configured with CA/DC the term ‘serving cells’ is used todenote the set of cells comprising of the Special Cell(s) and allsecondary cells.

In NR the term Master Cell Group (MCG) refers to a group of servingcells associated with the Master Node, comprising of the PCell andoptionally one or more SCells. In NR the term Secondary Cell Group (SCG)refers to a group of serving cells associated with the Secondary Node,comprising of the PSCell and optionally one or more SCells. In NR PCell(primary cell) refers to a serving cell in MCG, operating on the primaryfrequency, in which the UE either performs the initial connectionestablishment procedure or initiates the connection re-establishmentprocedure. In NR for a UE configured with CA, Scell is a cell providingadditional radio resources on top of Special Cell. Primary SCG Cell(PSCell) refers to a serving cell in SCG in which the UE performs randomaccess when performing the Reconfiguration with Sync procedure. For DualConnectivity operation the term SpCell (i.e. Special Cell) refers to thePCell of the MCG or the PSCell of the SCG, otherwise the term SpecialCell refers to the PCell.

In NR bandwidth adaptation (BA) is supported. With BA, the receive andtransmit bandwidth of a UE need not be as large as the bandwidth of thecell and can be adjusted: the width can be ordered to change (e.g. toshrink during period of low activity to save power); the location canmove in the frequency domain (e.g. to increase scheduling flexibility);and the subcarrier spacing can be ordered to change (e.g. to allowdifferent services). A subset of the total cell bandwidth of a cell isreferred to as a Bandwidth Part (BWP) and BA is achieved by configuringthe UE with BWP(s) and telling the UE which of the configured BWPs iscurrently the active one.

When BA is configured, the UE only has to monitor PDCCH on the oneactive BWP i.e. it does not have to monitor PDCCH on the entire DLfrequency of the serving cell. A serving cell is configured with one ormore BWPs, and for a serving cell, there is always one active BWP at anypoint in time. The BWP switching for a serving cell is used to activatean inactive BWP and deactivate an active BWP at a time. The BWPswitching is controlled by the PDCCH indicating a downlink assignment oran uplink grant, or by RRC signaling. Additionally, a BWP inactivitytimer is used to switch the active DL BWP to the default DL BWP orinitial DL BWP of a serving cell. One of the configured BWPs of aserving cell can be a default DL BWP and is indicated in BWPconfiguration received from gNB. Initial DL BWP is also signaled (eitherin system information or in dedicated signaling). One of the configuredBWPs of a serving cell can be a first active DL BWP and is indicated inBWP configuration received from gNB. It is to be noted that BWPinactivity timer may or may not be configured in BWP configuration ofeach serving cell received from gNB. BWP inactivity timer if configured,is signaled independently for each serving cell. None or multipleserving cells may be configured with BWP inactivity timer.

In fifth generation wireless communication system UE may perform randomaccess procedure for various reasons such as for UL timing alignment,requesting UL grant or for requesting on demand SI etc. During therandom access procedure if BWP is switched (e.g. if BWP inactivity timerexpires) then UE will have to abort the ongoing random access procedureand restart it again in newly activated BWP. This leads to increaseddelay in completing the random access procedure. So, a method tominimize the interruption is needed.

If BWP inactivity timer is configured for an activated serving cell, theMAC entity in UE shall for this activated Serving Cell performs thefollowing operations according to the current procedure:

-   -   A) If the Default-DL-BWP is configured, and the active DL BWP is        not the BWP indicated by the Default-DL-BWP; or if the        Default-DL-BWP is not configured, and the active DL BWP is not        the initial DL BWP:        -   if a PDCCH addressed to C-RNTI or CS-RNTI indicating            downlink assignment or uplink grant is received on the            active BWP; or if a MAC PDU is transmitted in a configured            uplink grant or received in a configured downlink            assignment;            -   start or restart the BWP-InactivityTimer associated with                the active DL BWP;    -   B) If a PDCCH for BWP switching is received, and the MAC entity        switches the active BWP:        -   if the defaultDownlinkBWP-Id is configured, and the MAC            entity switches to the BWP which is not indicated by the            defaultDownlinkBWP-Id; or if the defaultDownlinkBWP-Id is            not configured, and the MAC entity switches to the BWP which            is not the initialDownlinkBWP:            -   start or restart the bwp-InactivityTimer associated with                the active DL BWP.    -   C) if random access procedure is initiated on this serving cell:        -   stop the BWP-InactivityTimer;    -   D) if BWP-InactivityTimer associated with the active DL BWP        expires:        -   if the Default-DL-BWP is configured, perform BWP switching            to a BWP indicated by the Default-DL-BWP. Otherwise, perform            BWP switching to the initial DL BWP.

There are several issues with operation (as described above) of BWPinactivity timer. If random access (RA) procedure is initiated, UE stopsthe BWP-InactivityTimer according to current procedure. UE stops theBWP-InactivityTimer associated with active DL BWP of activated servingcell for which the random access is initiated. If the random access isinitiated for PCell, BWP-InactivityTimer associated with active DL BWPof PCell is stopped. If the random access is initiated for SCell,BWP-InactivityTimer associated with active DL BWP of SCell is stopped.In case of random access procedure on SCell (other than PSCell), onlyPRACH preamble is transmitted on SCell. UE receives the RAR on SpCell.The active DL BWP on SpCell can switch while random access procedure isongoing. This will lead to interruption as random access procedure needsto be stopped and restarted after the BWP switching.

FIG. 1 illustrates an operation of the BWP-InactivityTimer associatedwith the random access procedure according to an embodiment of thedisclosure.

Referring to FIG. 1, random access procedure is initiated at T=t1 (100)and completes at T=t3 (120). While random access procedure is ongoing,UE may receive a PDCCH with downlink assignment (for e.g. UE may receivea PDCCH with downlink assignment for RAR). In this scenario, UE stopsthe BWP-InactivityTimer at T=t1 (100) in order to prevent BWP switchingduring random access procedure. However, BWP switching cannot be avoidedas UE restarts BWP-InactivityTimer again at T=t2 (110) during the randomaccess procedure. This will also lead to interruption as random accessprocedure needs to be stopped and restarted after the BWP switching.

In the invention, for Dual/multi Connectivity operation the term SpecialCell (SpCell) refers to the primary cell (PCell) of the Master CellGroup (MCG) or the primary secondary cell (PSCell) of the Secondary CellGroup (SCG) depending on if the MAC entity is associated to the MCG orthe SCG, respectively. There is one MAC entity per Cell Group (CG) inUE. Otherwise the term Special Cell refers to the PCell. In the proposedoperation if the SCell on which random access procedure is initiatedbelongs to MCG then term SpCell refers to PCell. If the SCell on whichrandom access procedure is initiated belongs to SCG then term SpCellrefers to PSCell.

In one method of the invention it is proposed to handle BWP Inactivitytimer upon initiation of random access procedure according to the typeof serving cell on which random access procedure is Initiated.

The random access procedure is initiated by a PDCCH order from gNB, bythe MAC entity itself, by beam failure indication from lower layer, orby RRC. For example, the random access procedure is initiated orperformed for the following events related to the PCell:

-   -   Initial access from RRC IDLE;    -   RRC Connection Re-establishment procedure;    -   Handover;    -   DL data arrival during RRC_CONNECTED requiring random access        procedure:        -   E.g. when UL synchronisation status is “non-synchronised”.    -   UL data arrival during RRC_CONNECTED requiring random access        procedure:        -   E.g. when UL synchronisation status is “non-synchronised” or            there are no PUCCH resources for SR available.    -   For positioning purpose during RRC_CONNECTED requiring random        access procedure;        -   E.g. when timing advance is needed for UE positioning.    -   Transition from RRC INACTIVE;    -   Request for Other SI

The random access procedure is also performed on a SCell to establishtime alignment for the corresponding sTAG. In DC, the random accessprocedure is also performed on at least PSCell upon SCGaddition/modification, if instructed, or upon DL/UL data arrival duringRRC_CONNECTED requiring random access procedure. The UE initiated randomaccess procedure is performed only on PSCell for SCG.

According to current procedure MAC entity in UE perform the followingoperation for each activated serving cell configured with BWP inactivitytimer:

If the Default-DL-BWP is configured, and the active DL BWP is not theBWP indicated by the Default-DL-BWP; or if the Default-DL-BWP is notconfigured, and the active DL BWP is not the initial BWP:

-   -   If random access procedure is initiated, UE stops the        BWP-InactivityTimer. UE stops the BWP-InactivityTimer associated        with active DL BWP of activated serving cell for which the        random access is initiated. This means that if the random access        is initiated for PCell, BWP-InactivityTimer associated with        active DL BWP of PCell is stopped. If the random access is        initiated for PSCell, BWP-InactivityTimer associated with active        DL BWP of PSCell is stopped. If the random access is initiated        for SCell (i.e. secondary cell other than PSCell),        BWP-InactivityTimer associated with active DL BWP of SCell is        stopped.

In case of random access procedure on SCell (other than PSCell), onlyPRACH preamble is transmitted on SCell. UE receives the RAR on SpCell.The active DL BWP on SpCell can switch while random access procedure isongoing. This will lead to interruption as random access procedure needsto be stopped and restarted after BWP switching.

In order to resolve the issue, in an embodiment of the invention wepropose the following UE operation:

Step 1: random access procedure is initiated on a serving cell.

Step 2: If the serving cell on or for which random access procedure isinitiated is a SCell (i.e. secondary cell other than PSCell), UEperforms operation described in step 3 and step 4. Otherwise, UEperforms operation described in step 3.

Step 3: For the serving cell on or for which random access procedure isinitiated, UE performs the following:

-   -   A. if BWP inactivity timer is configured and if the        Default-DL-BWP is configured, and the active DL BWP is not the        BWP indicated by the Default-DL-BWP, MAC entity stops        BWP-InactivityTimer (i.e. MAC entity stops BWP-InactivityTimer        of this serving cell or MAC entity stops BWP-InactivityTimer        associated with active DL BWP of this serving cell);        -   OR    -   B. if BWP inactivity timer is configured and if the        Default-DL-BWP is not configured, and the active DL BWP is not        the initial DL BWP, MAC entity stops BWP-InactivityTimer (i.e.        MAC entity stops BWP-InactivityTimer of this serving cell or MAC        entity stops BWP-InactivityTimer associated with active DL BWP        of this serving cell);

Step 4: For the special serving cell (SpCell) UE performs the following:

-   -   A. if BWP inactivity timer is configured and if the        Default-DL-BWP is configured, and the active DL BWP is not the        BWP indicated by the Default-DL-BWP, MAC entity stops        BWP-InactivityTimer (i.e. MAC entity stops BWP-InactivityTimer        of SpCell or MAC entity stops BWP-InactivityTimer associated        with active DL BWP of SpCell);        -   OR    -   B. if BWP inactivity timer is configured and if the        Default-DL-BWP is not configured, and the active DL BWP is not        the initial BWP, MAC entity stops BWP-InactivityTimer (i.e. MAC        entity stops BWP-InactivityTimer of SpCell or MAC entity stops        BWP-InactivityTimer associated with active DL BWP of SpCell);

FIG. 2 illustrates UE operation in one embodiment of the proposedinvention to handle BWP-InactivityTimer upon initiation of random accessprocedure according to the type of serving cell on which random accessprocedure is initiated according to an embodiment of the disclosure.

Referring to FIG. 2, the UE operation includes the followingsteps/operations.

In operation 200, random access procedure is initiated

In operation 210, if the serving cell on or for which random accessprocedure is initiated is a SCell (i.e. secondary cell other thanPSCell), UE performs operation described in operation 220 and operation230. Otherwise, UE performs operation described in operation 240 whichis the same as the operation 220.

In operation 220, for the serving cell on or for which random accessprocedure is initiated, UE performs the following:

-   -   A. if BWP inactivity timer is running for this serving cell,        stop the BWP-InactivityTimer for this serving cell; In alternate        embodiment, if BWP inactivity timer is running for this serving        cell, stop the BWP-InactivityTimer associated with active DL BWP        of this serving cell.

In operation 230, for the special serving cell (SpCell) UE performs thefollowing:

-   -   B. if BWP inactivity timer is running for SpCell, stop the        BWP-InactivityTimer of SpCell; In alternate embodiment, if BWP        inactivity timer is running for SpCell, stop the        BWP-InactivityTimer associated with active DL BWP of SpCell.

FIG. 3 illustrates UE operation in another embodiment of the proposedinvention to handle BWP-InactivityTimer upon initiation of random accessprocedure according to the type of serving cell on which random accessprocedure is initiated according to an embodiment of the disclosure. Inan embodiment, upon initiation of random access procedure this operationis performed by MAC entity in UE for each activated serving cell whichare configured with BWP inactivity timer. In another embodiment, uponinitiation of random access procedure this operation is performed by MACentity in UE for following serving cells:

-   -   a) for serving cell on which random access procedure is        initiated if BWP inactivity timer is configured on this serving        cell.    -   b) for SpCell if the serving cell on which random access        procedure is initiated is not SpCell and if BWP inactivity timer        is configured for SpCell.

Referring to FIG. 3, the UE operation includes the followingsteps/operations.

-   1> If the Default-DL-BWP is configured, and the active DL BWP is not    the BWP indicated by the Default-DL-BWP; operation 300 or-   1> if the Default-DL-BWP is not configured, and the active DL BWP is    not the initial BWP operation 330:    -   2> if random access procedure is initiated on or for this        serving cell operation 310:        -   3> stop the BWP-InactivityTimer of this serving cell            operation 320; In alternate embodiment, if BWP inactivity            timer is running for this serving cell, stop the            BWP-InactivityTimer associated with active DL BWP of this            serving cell.    -   2> else if random access procedure is initiated on or for        another serving cell and if this serving cell is SpCell        operation 340:        -   3> stop the BWP-InactivityTimer of this serving cell            operation 320; In alternate embodiment, if BWP inactivity            timer is running for this serving cell, stop the            BWP-InactivityTimer associated with active DL BWP of this            serving cell.

FIG. 4 illustrates UE operation in another embodiment of the proposedinvention to handle BWP-InactivityTimer upon initiation of random accessprocedure according to the type of serving cell on which random accessprocedure is initiated according to an embodiment of the disclosure.Referring to FIG. 4, upon initiation of random access procedure thisoperation is performed by MAC entity in UE for serving cell on whichrandom access procedure is initiated.

In operation 400, random access procedure is initiated on a servingcell.

For this serving cell the BWP inactivity timer is operated by the UE asfollows:

-   1> If the Default-DL-BWP is configured, and the active DL BWP is not    the BWP indicated by the Default-DL-BWP (operation 410); or-   1> if the Default-DL-BWP is not configured, and the active DL BWP is    not the initial BWP (operation 450):    -   2> stop the BWP-InactivityTimer of this serving cell, if running        (operation 420); In alternate embodiment, if BWP inactivity        timer is running, stop the BWP-InactivityTimer associated with        active DL BWP of this serving cell.    -   2> if this serving cell is SCell (i.e. secondary cell other than        PSCell) (operation 430):        -   3> stop the BWP-InactivityTimer of SpCell, if running            (operation 440); In alternate embodiment, if BWP inactivity            timer is running, stop the BWP-InactivityTimer associated            with active DL BWP of SpCell.

FIG. 5 illustrates UE operation in another embodiment of the proposedinvention to handle BWP-InactivityTimerupon initiation of random accessprocedure according to the type of serving cell on which random accessprocedure is initiated according to an embodiment of the disclosure.Referring to FIG. 5, upon initiation of random access procedure thisoperation is performed by MAC entity in UE for serving cell on whichrandom access procedure is initiated.

In operation 500, random access procedure is initiated on a servingcell.

-   1> If the Default-DL-BWP is configured, and the active DL BWP is not    the BWP indicated by the Default-DL-BWP (operation 510); or-   1> if the Default-DL-BWP is not configured, and the active DL BWP is    not the initial BWP (operation 560):    -   2> stop the BWP-InactivityTimer of this serving cell (operation        520); In alternate embodiment, if BWP inactivity timer is        running, stop the BWP-InactivityTimer associated with active DL        BWP of this serving cell.    -   2> if this serving cell is SCell (i.e. secondary cell other than        PSCell) (operation 530):        -   3> if BWP inactivity timer is configured for the SpCell:            -   4> For the SpCell, If the Default-DL-BWP is configured,                and the active DL BWP is not the BWP indicated by the                Default DL-BWP (operation 540); or            -   4> For the SpCell, if the Default-DL-BWP is not                configured, and the active DL BWP is not the initial BWP                (operation 570);                -   5> stop the BWP-InactivityTimer of SpCell (operation                    550); In alternate embodiment, if BWP inactivity                    timer is running, stop the BWP-InactivityTimer                    associated with active DL BWP of SpCell.

In the above operation expression ‘random access procedure is initiatedon or for a serving cell’ means the random access procedure in whichPRACH preamble is transmitted on the said serving cell.

Alternatively, it is proposed to handle BWP Inactivity timer uponinitiation of random access procedure according to the type of servingcell on which random access procedure is Initiated.

According to current procedure, MAC entity in UE perform the followingoperation for each activated serving cell configured with BWP inactivitytimer:

If the Default-DL-BWP is configured, and the active DL BWP is not theBWP indicated by the Default-DL-BWP; or if the Default-DL-BWP is notconfigured, and the active DL BWP is not the initial BWP:

-   -   If random access procedure is initiated, UE stops the        BWP-InactivityTimer. UE stops the BWP-InactivityTimer associated        with active DL BWP of activated serving cell for which the        random access is initiated. This means that if the random access        is initiated for PCell, BWP-InactivityTimer associated with        active DL BWP of PCell is stopped. If the random access is        initiated for PSCell, BWP-InactivityTimer associated with active        DL BWP of PSCell is stopped. If the random access is initiated        for SCell (other than PSCell), BWP-InactivityTimer associated        with active DL BWP of SCell is stopped.

In case of random access procedure on SCell (other than PSCell), onlyPRACH preamble is transmitted on SCell. UE receives the RAR on SpCell.The active DL BWP on SpCell can switch while random access procedure isongoing. This will lead to interruption as random access procedure needsto be stopped and restarted after BWP switching.

In order to resolve the issue, we propose the following UE operation:

Step 1: random access procedure is initiated.

Step 2: If the serving cell on or for which random access procedure isinitiated is a SCell (i.e. secondary cell other than PSCell), UEperforms operation described in step 3 and step 4. Otherwise, UEperforms operation described in step 3.

Step 3: For the serving cell on or for which random access procedure isinitiated, UE performs the following:

-   -   A. if BWP inactivity timer is configured and if the        Default-DL-BWP is configured, and the active DL BWP is not the        BWP indicated by the Default-DL-BWP, MAC entity stops        BWP-InactivityTimer; (i.e. MAC entity stops BWP-InactivityTimer        of this serving cell or MAC entity stops BWP-InactivityTimer        associated with active DL BWP of this serving cell);    -   OR    -   B. if serving cell is PCell and if BWP inactivity timer is        configured and if the Default-DL-BWP is not configured, and the        active DL BWP is not the initial BWP, MAC entity stops        BWP-InactivityTimer (i.e. MAC entity stops BWP-InactivityTimer        of this serving cell or MAC entity stops BWP-InactivityTimer        associated with active DL BWP of this serving cell);    -   OR    -   C. if serving cell is SCell and if BWP inactivity timer is        configured and if the Default-DL-BWP is not configured, and the        active DL BWP is not the first active BWP, MAC entity stops        BWP-InactivityTimer (i.e. MAC entity stops BWP-InactivityTimer        of this serving cell or MAC entity stops BWP-InactivityTimer        associated with active DL BWP of this serving cell); (Note, this        condition may be absent in an embodiment of the proposed        invention)

Step 4: For the special serving cell (SpCell) UE performs the following:

-   -   A. if BWP inactivity timer is configured and if the        Default-DL-BWP is configured, and the active DL BWP is not the        BWP indicated by the Default-DL-BWP, MAC entity stops        BWP-InactivityTimer (i.e. MAC entity stops BWP-InactivityTimer        of this serving cell or MAC entity stops BWP-InactivityTimer        associated with active DL BWP of this serving cell);    -   OR    -   B. if serving cell is PCell and if BWP inactivity timer is        configured and if the Default-DL-BWP is not configured, and the        active DL BWP is not the initial BWP, MAC entity stops        BWP-InactivityTimer (i.e. MAC entity stops BWP-InactivityTimer        of this serving cell or MAC entity stops BWP-InactivityTimer        associated with active DL BWP of this serving cell);    -   OR    -   C. if serving cell is SCell and if BWP inactivity timer is        configured and if the Default-DL-BWP is not configured, and the        active DL BWP is not the first active BWP, MAC entity stops        BWP-InactivityTimer (i.e. MAC entity stops BWP-InactivityTimer        of this serving cell or MAC entity stops BWP-InactivityTimer        associated with active DL BWP of this serving cell); (Note, this        condition may be absent in an embodiment of the proposed        invention).

In another embodiment of the proposed invention, upon initiation ofrandom access procedure MAC entity in UE perform the followingoperation. In an embodiment, upon initiation of random access procedurethis operation is performed by MAC entity in UE for each activatedserving cell which are configured with BWP inactivity timer. In anotherembodiment, upon initiation of random access procedure this operation isperformed by MAC entity in UE for following serving cells:

-   -   a) for serving cell on which random access procedure is        initiated if BWP inactivity timer is configured on this serving        cell.    -   b) for SpCell if the serving cell on which random access        procedure is initiated is not SpCell and if BWP inactivity timer        is configured for SpCell:

-   1> If the Default-DL-BWP is configured, and the active DL BWP is not    the BWP indicated by the Default-DL-BWP; or

-   1> if this serving cell is PCell and if the Default-DL-BWP is not    configured, and the active DL BWP is not the initial BWP; or

-   1> if this serving cell is SCell and if the Default-DL-BWP is not    configured, and the active DL BWP is not the first active BWP:    -   2> if random access procedure is initiated on or for this        serving cell:        -   3> stop the BWP-InactivityTimer associated with active DL            BWP of this serving cell; In alternate embodiment, if BWP            inactivity timer is running, stop the BWP-InactivityTimer of            this serving cell.    -   2> else if random access procedure is initiated on or for        another serving cell and if this serving cell is SpCell:        -   3> stop the BWP-InactivityTimer associated with active DL            BWP of this serving cell; In alternate embodiment, if BWP            inactivity timer is running, stop the BWP-InactivityTimer            associated with active DL BWP of this serving cell.

In another embodiment of the proposed invention, upon initiation ofrandom access procedure on a serving cell the MAC entity in UE performthe following operation for this serving cell:

-   1> If the Default-DL-BWP is configured, and the active DL BWP is not    the BWP indicated by the Default-DL-BWP; or-   1> if the Default-DL-BWP is not configured, and the active DL BWP is    not the initial BWP; or-   1> if this serving cell is SCell and if the Default-DL-BWP is not    configured, and the active DL BWP is not the first active BWP:    -   2> stop the BWP-InactivityTimer associated with active DL BWP of        this serving cell; In alternate embodiment, if BWP inactivity        timer is running, stop the BWP-InactivityTimer of this serving        cell.    -   2> if this serving cell is SCell (i.e. secondary cell other than        PSCell):        -   3> stop the BWP-InactivityTimer associated with active DL            BWP of SpCell, if running; In alternate embodiment, if BWP            inactivity timer is running, stop the BWP-InactivityTimer of            SpCell, if running.

In another embodiment of the proposed invention, upon initiation ofrandom access procedure on a serving cell the MAC entity in UE performthe following operation for this serving cell:

-   1> If the Default-DL-BWP is configured, and the active DL BWP is not    the BWP indicated by the Default-DL-BWP; or-   1> if the Default-DL-BWP is not configured, and the active DL BWP is    not the initial BWP; or-   1> if this serving cell is SCell and if the Default-DL-BWP is not    configured, and the active DL BWP is not the first active BWP:    -   2> stop the BWP-InactivityTimer associated with active DL BWP of        this serving cell; In alternate embodiment, if BWP inactivity        timer is running, stop the BWP-InactivityTimer of this serving        cell.    -   2> if this serving cell is SCell (i.e. secondary cell other than        PSCell):        -   3> if BWP inactivity timer is configured for the SpCell:            -   4> For the SpCell, If the Default-DL-BWP is configured,                and the active DL BWP is not the BWP indicated by the                Default-DL-BWP; or            -   4> For the SpCell, if the Default-DL-BWP is not                configured, and the active DL BWP is not the initial                BWP;                -   5> stop the BWP-InactivityTimer associated with                    active DL BWP of SpCell; In alternate embodiment, if                    BWP inactivity timer is running, stop the                    BWP-InactivityTimer of SpCell.

In the above operation expression ‘random access procedure is initiatedon or for a serving cell’ means the random access procedure in whichPRACH preamble is transmitted on the said serving cell. The first activeBWP amongst the configured BWP is indicated in BWP configurationreceived from gNB.

In one method of the invention it is proposed to handle BWP Inactivitytimer upon completion of random access procedure.

Some examples of conditions when random access procedure is consideredsuccessfully completed are as follows:

-   1. After transmitting the contention free Random Access Preamble for    beam failure recovery request, UE receives PDCCH transmission    addressed to the C-RNTI in bfr-response window.-   2. After transmitting the contention free Random Access Preamble for    SI request if a downlink assignment has been received on the PDCCH    for the RA-RNTI and the received TB is successfully decoded and if    the Random Access Response contains a Random Access Preamble    identifier corresponding to the transmitted preamble and if the    Random Access Response includes RAPID only.-   3. After transmitting the contention free Random Access Preamble if    a downlink assignment has been received on the PDCCH for the RA-RNTI    and the received TB is successfully decoded and if the Random Access    Response contains a Random Access Preamble identifier corresponding    to the transmitted preamble and if the Random Access Response does    not include RAPID only.-   4. After transmitting Msg3, if PDCCH is received and if the C-RNTI    MAC CE was included in Msg3 and if the random access procedure was    initiated by the MAC sublayer itself or by the RRC sublayer and the    PDCCH transmission is addressed to the C-RNTI and contains an UL    grant for a new transmission.-   5. After transmitting Msg3, if PDCCH is received and if the C-RNTI    MAC CE was included in Msg3 and if the random access procedure was    initiated by a PDCCH order and the PDCCH transmission is addressed    to the C-RNTI.-   6. After transmitting Msg3, if PDCCH is received and if the C-RNTI    MAC CE was included in Msg3 and if the random access procedure was    initiated for beam failure recovery and the PDCCH transmission is    addressed to the C-RNTI.-   7. After transmitting Msg3, if PDCCH is received and if the CCCH SDU    was included in Msg3 and the PDCCH transmission is addressed to its    TEMPORARY_C-RNTI and if the MAC PDU is successfully decoded and if    the MAC PDU contains a UE Contention Resolution Identity MAC CE; and    if the UE Contention Resolution Identity in the MAC CE matches the    CCCH SDU transmitted in Msg3:

In the one embodiment of the proposed invention, UE operation is asfollows:

Step 1: random access procedure initiated on or for a serving cell issuccessfully completed

Step 2: If the serving cell on which random access procedure (which wassuccessfully completed) was initiated is a SCell (i.e. secondary cellother than PSCell), UE performs operation described in step 3 and step4. Otherwise, UE performs operation described in step 3.

Step 3: For the serving cell on which random access procedure (which wassuccessfully completed) was initiated, UE performs the following:

-   -   A. if BWP inactivity timer is configured and if the        Default-DL-BWP is configured, and the active DL BWP is not the        BWP indicated by the Default-DL-BWP, MAC entity starts        BWP-InactivityTimer (i.e. start the BWP-InactivityTimer        associated with active DL BWP of this serving cell or start the        BWP-InactivityTimer of this serving cell);    -   OR    -   B. if BWP inactivity timer is configured and if the        Default-DL-BWP is not configured, and the active DL BWP is not        the initial DL BWP, MAC entity starts BWP-InactivityTimer (i.e.        start the BWP-InactivityTimer associated with active DL BWP of        this serving cell or start the BWP-InactivityTimer of this        serving cell);

Step 4: For the special serving cell (SpCell) UE performs the following:

-   -   C. if BWP inactivity timer is configured and if the        Default-DL-BWP is configured, and the active DL BWP is not the        BWP indicated by the Default-DL-BWP, MAC entity starts        BWP-InactivityTimer (i.e. start the BWP-InactivityTimer        associated with active DL BWP of this serving cell or start the        BWP-InactivityTimer of this serving cell);    -   OR    -   D. if BWP inactivity timer is configured and if the        Default-DL-BWP is not configured, and the active DL BWP is not        the initial DL BWP, MAC entity starts BWP-InactivityTimer (i.e.        start the BWP-InactivityTimer associated with active DL BWP of        this serving cell or start the BWP-InactivityTimer of this        serving cell);

Note: For Dual/multi Connectivity operation the term Special Cell(SpCell) refers to the PCell of the MCG or the PSCell of the SCGdepending on if the MAC entity is associated to the MCG or the SCG,respectively. Otherwise the term Special Cell refers to the Pcell).

FIG. 6 illustrates UE operation in one embodiment of the proposedinvention to handle BWP-InactivityTimer upon completion of random accessprocedure according to an embodiment of the disclosure.

Referring to FIG. 6, in operation 600, random access procedure initiatedis successfully completed.

In operation 610, if the serving cell on which random access procedure(which was successfully completed) was initiated is a SCell (i.e.secondary cell other than PSCell), UE performs operation described inoperation 620 and operation 630. Otherwise, UE performs operationdescribed in operation 640 which is the same as the operation 620.

In operation 620, for the serving cell on or for which random accessprocedure (which was successfully completed) was initiated, UE performsthe following:

-   -   A. start the BWP-InactivityTimer for this serving cell; In        alternate embodiment, start the BWP-InactivityTimer associated        with active DL BWP of this serving cell.

In operation 630, for the special serving cell (SpCell) UE performs thefollowing:

-   -   B. Start the BWP-InactivityTimer of SpCell; In alternate        embodiment, start the BWP-InactivityTimer associated with active        DL BWP of SpCell.

FIG. 7 illustrates UE operation in another embodiment of the proposedinvention to handle BWP-InactivityTimer upon completion of random accessprocedure according to an embodiment of the disclosure. Referring toFIG. 7, in an embodiment, upon completion of random access procedurethis operation is performed by MAC entity in UE for each activatedserving cell which are configured with BWP inactivity timer. In anotherembodiment, upon completion of random access procedure this operation isperformed by MAC entity in UE for following serving cells:

-   -   a) for serving cell on which the completed random access        procedure was initiated if BWP inactivity timer is configured on        this serving cell.    -   b) for SpCell if the serving cell on which the completed random        access procedure was initiated is not SpCell and if BWP        inactivity timer is configured for SpCell.

-   1> If the Default-DL-BWP is configured, and the active DL BWP is not    the BWP indicated by the Default-DL-BWP (operation 700); or

-   1> if the Default-DL-BWP is not configured, and the active DL BWP is    not the initial BWP (operation 730):    -   2> if random access procedure initiated on this serving cell is        successfully completed (operation 710):        -   3> start the BWP-InactivityTimer (i.e. start the            BWP-InactivityTimer associated with active DL BWP of this            serving cell or start the BWP-InactivityTimer of this            serving cell) (operation 720);    -   2> else if random access procedure is initiated on another        serving cell and if this serving cell is SpCell (operation 740)        -   3> start the BWP-InactivityTimer associated (i.e. start the            BWP-InactivityTimer associated with active DL BWP of this            serving cell or start the BWP-InactivityTimer of this            serving cell) (operation 720);

FIG. 8 illustrates UE operation in another embodiment of the proposedinvention to handle BWP-InactivityTimer when random access procedure iscompleted according to an embodiment of the disclosure. Referring toFIG. 8, upon completion of random access procedure this operation isperformed by MAC entity in UE for serving cell on which the completedrandom access procedure was initiated.

In operation 800, random access procedure is successfully completed.

If BWP inactivity timer is configured, the BWP inactivity timer isoperated by the UE as follows:

-   1> If the Default-DL-BWP is configured, and the active DL BWP is not    the BWP indicated by the Default-DL-BWP (operation 810); or-   1> if the Default-DL-BWP is not configured, and the active DL BWP is    not the initial BWP (operation 850):    -   2> start the BWP-InactivityTimer (i.e. start the        BWP-InactivityTimer associated with active DL BWP of this        serving cell or start the BWP-InactivityTimer of this serving        cell) (operation 820);    -   2> if this serving cell is SCell (i.e. secondary cell other than        PSCell) (operation 830):        -   3> start the BWP-InactivityTimer of SpCell, if configured            (i.e. start the BWP-InactivityTimer associated with active            DL BWP of SpCell or start the BWP-InactivityTimer of SpCell)            (operation 840);

FIG. 9 illustrates UE operation in another embodiment of the proposedinvention to handle BWP-InactivityTimer when random access procedure iscompleted according to an embodiment of the disclosure. Referring toFIG. 9, upon completion of random access procedure this operation isperformed by MAC entity in UE for serving cell on which the completedrandom access procedure was initiated.

In operation 900, random access procedure is successfully completed.

-   1> If the Default-DL-BWP is configured, and the active DL BWP is not    the BWP indicated by the Default-DL-BWP (operation 910); or-   1> if the Default-DL-BWP is not configured, and the active DL BWP is    not the initial BWP (operation 960):    -   2> start the BWP-InactivityTimer (i.e. start the        BWP-InactivityTimer associated with active DL BWP of this        serving cell or start the BWP-InactivityTimer of this serving        cell) (operation 920);    -   2> if this serving cell is SCell (i.e. secondary cell other than        PSCell) (operation 930):        -   3> if BWP inactivity timer is configured for the SpCell:            -   4> If the Default-DL-BWP is configured, and the active                DL BWP is not the BWP indicated by the Default-DL-BWP                (operation 940); or            -   4> if the Default-DL-BWP is not configured, and the                active DL BWP is not the initial BWP (operation 970);                -   5> start the BWP-InactivityTimer of SpCell (i.e.                    start the BWP-InactivityTimer associated with active                    DL BWP of this SpCell or start the                    BWP-InactivityTimer of SpCell) (operation 950);

In one method of the invention it is proposed to handle BWP Inactivitytimer when PDCCH with DL Assignment is received on or for the active DLBWP

If random access procedure is initiated, UE stops theBWP-InactivityTimer. The purpose of stopping the BWP-InactivityTimer isto prevent BWP switching (i.e. switching to default BWP or initial BWP)during the random access procedure. If the Default-DL-BWP is configured,and the active DL BWP is not the BWP indicated by the Default-DL-BWP; orif the Default-DL-BWP is not configured, and the active DL BWP is notthe initial BWP: if a PDCCH indicating downlink assignment is receivedon the active BWP, MAC entity in UE starts or restarts theBWP-InactivityTimer associated with the active DL BWP. In abovementionedprocedure, BWP switching cannot be avoided as UE may restartBWP-InactivityTimer during the random access procedure. This leads tointerruption as random access procedure needs to be stopped andrestarted upon BWP switching.

In an embodiment of the proposed invention we propose that the UE followthe operation as illustrated in FIG. 10 when UE receives a PDCCHindicating DL assignment for an active DL BWP of a serving cell.

FIG. 10 illustrates UE operation in one embodiment of the proposedinvention to handle BWP-InactivityTimer when PDCCH with DL Assignment isreceived for the active DL BWP according to an embodiment of thedisclosure.

Referring to FIG. 10, in operation 1000, PDCCH indicating DL assignmentfor an active DL BWP X may be received in active DL BWP X or it may bereceived in another active DL BWP Y. For example, PDCCH received in DLBWP Y may include DL assignment for DL BWP X. DL BWP X and Y may be theBWPs of same serving cell or different serving cells.

In operation 1010, if there is any ongoing random access procedureassociated with the serving cell of active DL BWP for which DLassignment is received, UE does not (re-)start BWP-InactivityTimerassociated with active DL BWP for which the DL assignment is received inoperation 1020. A random access procedure is associated with servingcell if the PRACH preamble was transmitted on the serving cell by UEand/or UE receives RAR on the serving cell. In some cases, multipleserving cells can be associated with a random access procedure. Forexample, when random access procedure is initiated for SCell (i.e.secondary cell other than PSCell) wherein UE transmits PRACH preamble onSCell and receives RAR on SpCell. So, in this case, random accessprocedure is associated with SCell as well as SpCell. For example, ifrandom access procedure is initiated on SpCell, UE transmits PRACHpreamble on SpCell and receives RAR on SpCell. So, in this case, randomaccess procedure is associated with SpCell.

In operation 1010, if there is no ongoing random access procedureassociated with the serving cell of active DL BWP for which DLassignment is received, UE does (re-)start BWP-InactivityTimerassociated with active DL BWP for which the DL assignment is received inoperation 1030.

In another embodiment of the proposed invention, MAC entity in UEperform the following operation for each activated serving cellconfigured with BWP inactivity timer:

-   1> If the Default-DL-BWP is configured, and the active DL BWP is not    the BWP indicated by the Default-DL-BWP; or-   1> if the Default-DL-BWP is not configured, and the active DL BWP is    not the initial DL BWP:    -   2> if a PDCCH addressed to C-RNTI or CS-RNTI indicating downlink        assignment is received on the active DL BWP of this serving        cell:        -   3> if there is no ongoing random access procedure associated            with this Serving cell:            -   4> start or restart the BWP-InactivityTimer of this                serving cell (i.e. start or restart the                BWP-InactivityTimer associated with active DL BWP of                this serving cell or start the BWP-InactivityTimer of                this serving cell);

For example, UE receives a PDCCH addressed to C-RNTI or CS-RNTIindicating DL assignment. The PDCCH is received on an active DL BWP ofserving cell X. If there is no ongoing random access procedureassociated with serving cell X, UE (re-)starts BWP-InactivityTimerassociated with active DL BWP of serving cell X. In this embodiment, ifthere are multiple active DL BWPs in a serving cell, operation of startor restart the BWP-InactivityTimer of serving cell is for theBWP-InactivityTimer associated with active DL BWP on which PDCCHaddressed to C-RNTI or CS-RNTI indicating downlink assignment isreceived.

In another embodiment of the proposed invention, MAC entity in UEperform the following operation for each activated serving cellconfigured with BWP inactivity timer:

-   1> If the Default-DL-BWP is configured, and the active DL BWP is not    the BWP indicated by the Default-DL-BWP; or-   1> if the Default-DL-BWP is not configured, and the active DL BWP is    not the initial BWP:    -   2> if a PDCCH addressed to C-RNTI or CS-RNTI indicating downlink        assignment is received for the active DL BWP of this serving        cell (PDCCH indicating DL assignment for an active DL BWP X may        be received in same active DL BWP X or it may be received in        another active DL BWP Y. For example, PDCCH received in DL BWP Y        may include DL assignment for DL BWP X. DL BWP X and Y may be        the BWPs of same serving cell or different serving cell.):        -   3> if there is no ongoing random access procedure associated            with this serving cell:            -   4> start or restart the BWP-InactivityTimer of this                serving cell (i.e. star or restart the                BWP-InactivityTimer associated with active DL BWP of                this serving cell or start the BWP-InactivityTimer of                this serving cell);

For example, UE receives a PDCCH addressed to C-RNTI or CS-RNTIindicating DL assignment. The DL assignment is for active DL BWP ofserving cell X. If there is no ongoing random access procedureassociated with serving cell X, UE (re-) starts BWP-InactivityTimerassociated with active DL BWP of serving cell X. Note that PDCCHindicating this DL assignment may be received on active DL BWP ofserving cell X or another serving cell Y. In this embodiment, if thereare multiple active DL BWPs in a serving cell, operation of start orrestart the BWP-InactivityTimer is for the BWP-InactivityTimerassociated with active DL BWP for which downlink assignment is received.

In another embodiment of the proposed invention, MAC entity in UEperform the following operation for each activated serving cellconfigured with BWP inactivity timer:

-   1> If the Default-DL-BWP is configured, and the active DL BWP is not    the BWP indicated by the Default-DL-BWP; or-   1> if the Default-DL-BWP is not configured, and the active DL BWP is    not the initial BWP:    -   2> if a PDCCH addressed to C-RNTI or CS-RNTI indicating downlink        assignment is received on the active DL BWP; or    -   2> if a PDCCH addressed to C-RNTI or CS-RNTI indicating downlink        assignment is received for the active DL BWP (PDCCH indicating        DL assignment for an active DL BWP X may be received in same        active DL BWP X or it may be received in another active DL        BWP Y. For example, PDCCH received in DL BWP Y may include DL        assignment for DL BWP X. DL BWP X and Y may be the BWPs of same        serving cell or different serving cell.):        -   3> if there is no ongoing random access procedure associated            with this serving cell:            -   4> start or restart the BWP-InactivityTimer (i.e. start                or restart the BWP-InactivityTimer associated with                active DL BWP of this serving cell or start the                BWP-InactivityTimer of this serving cell);

In another embodiment of the proposed invention, MAC entity in UEperform the following operation for each activated serving cellconfigured with BWP inactivity timer:

-   1> if a PDCCH addressed to C-RNTI or CS-RNTI indicating downlink    assignment is received on or for the active DL BWP of a serving    cell:    -   2> if this serving cell is a SpCell:        -   3> if there is no ongoing random access procedure (no            ongoing random access procedure initiated on this serving            cell or any SCell of the CG associated with SpCell), start            or restart the BWP-InactivityTimer of this Serving Cell            (i.e. start or restart the BWP-InactivityTimer associated            with active DL BWP of this serving cell or start the            BWP-InactivityTimer of this serving cell);    -   2> else        -   3> if there is no ongoing random access procedure initiated            on this serving cell, start or restart the            BWP-InactivityTimer of this Serving Cell (i.e. start or            restart the BWP-InactivityTimer associated with active DL            BWP of this serving cell or start the BWP-InactivityTimer of            this serving cell)

In another embodiment of the proposed invention, MAC entity in UEperform the following operation for each activated serving cellconfigured with BWP inactivity timer:

-   1> if a PDCCH addressed to C-RNTI or CS-RNTI indicating downlink    assignment is received on or for the active DL BWP of a serving    cell:    -   2> if this serving cell is a SCell (i.e. secondary cell other        than PSCell):        -   3> if there is no ongoing random access procedure initiated            on this serving cell, start or restart the            BWP-InactivityTimer of this Serving Cell (i.e. start or            restart the BWP-InactivityTimer associated with active DL            BWP of this serving cell or start the BWP-InactivityTimer of            this serving cell);    -   2> else        -   3> if there is no ongoing random access procedure (no            ongoing random access procedure initiated on this serving            cell or any SCell of the CG associated with SpCell), start            or restart the BWP-InactivityTimer of this Serving Cell            (i.e. start or restart the BWP-InactivityTimer associated            with active DL BWP of this serving cell or start the            BWP-InactivityTimer of this serving cell).

In one method of the invention it is proposed to handle BWP Inactivitytimer when PDCCH with UL Grant is received on or for the active BWP

If random access procedure is initiated, UE stops theBWP-InactivityTimer. The purpose of stopping the BWP-InactivityTimer isto prevent BWP switching (i.e. switching to default BWP or initial BWP)during the random access procedure. If the Default-DL-BWP is configured,and the active DL BWP is not the BWP indicated by the Default-DL-BWP; orif the Default-DL-BWP is not configured, and the active DL BWP is notthe initial BWP: if a PDCCH indicating UL grant is received on or forthe active BWP; MAC entity starts or restarts the BWP-InactivityTimerassociated with the active DL BWP. In the abovementioned procedure, BWPswitching cannot be avoided as UE may restart BWP-InactivityTimer duringthe random access procedure. This leads to interruption as random accessprocedure needs to be stopped and restarted.

In an embodiment of the proposed invention we propose that UE follow theoperation as illustrated in FIG. 11 when UE receives a PDCCH indicatingUL grant for active BWP (i.e. active UL BWP).

FIG. 11 illustrates UE operation in one embodiment of the proposedinvention to handle BWP-InactivityTimer when PDCCH with UL Grant isreceived on the active BWP according to an embodiment of the disclosure.

Referring to FIG. 11, in operation 1100, a PDCCH indicating UL grant forthe active BWP is received.

In operation 1110, if there is any ongoing random access procedureassociated with the serving cell of active BWP for which UL grant isreceived, UE does not (re-)start BWP-InactivityTimer associated withactive DL BWP of this serving cell in operation 1120. A random accessprocedure is associated with serving cell if the PRACH preamble wastransmitted on the serving cell by UE and/or UE receives RAR on theserving cell. In some cases, multiple serving cells can be associatedwith random access procedure. For example, when random access procedureis initiated for SCell (other than PSCell) wherein UE transmits PRACHpreamble on SCell and receives RAR on SpCell. So, in this case, randomaccess procedure is associated with SCell as well as SpCell. Forexample, if random access procedure is initiated on SpCell, UE transmitsPRACH preamble on SpCell and receives RAR on SpCell. Thus, in this case,random access procedure is associated with SpCell.

In operation 1110, if there is no ongoing random access procedureassociated with the serving cell of active BWP for which UL grant isreceived, UE does (re-)start BWP-InactivityTimer associated with activeDL BWP for which the UL grant is received in operation 1130.

In another embodiment of the proposed invention, MAC entity in UEperform the following operation for each activated serving cellconfigured with BWP inactivity timer:

-   1> If the Default-DL-BWP is configured, and the active DL BWP is not    the BWP indicated by the Default-DL-BWP; or-   1> if the Default-DL-BWP is not configured, and the active DL BWP is    not the initial BWP:    -   2> if a PDCCH addressed to C-RNTI or CS-RNTI indicating uplink        grant is received on the active BWP of this serving cell:        -   3> if there is no ongoing random access procedure associated            with this Serving Cell:            -   4> start or restart the BWP-InactivityTimer of this                Serving Cell (i.e. start or restart the                BWP-InactivityTimer associated with active DL BWP of                this serving cell or (re-)start the BWP-InactivityTimer                of this serving cell);

For example, UE receives a PDCCH addressed to C-RNTI or CS-RNTIindicating uplink grant. The PDCCH is received on an active DL BWP ofserving cell X. If there is no ongoing random access procedureassociated with serving cell X, UE (re-)starts BWP-InactivityTimerassociated with active DL BWP of serving cell X. In this embodiment, ifthere are multiple active DL BWPs in a serving cell, operation of startor restart the BWP-InactivityTimer is for the BWP-InactivityTimerassociated with active DL BWP on which PDCCH addressed to C-RNTI orCS-RNTI indicating UL grant is received.

In another embodiment of the proposed invention, MAC entity in UEperform the following operation for each activated serving cellconfigured with BWP inactivity timer:

-   1> If the Default-DL-BWP is configured, and the active DL BWP is not    the BWP indicated by the Default-DL-BWP; or-   1> if the Default-DL-BWP is not configured, and the active DL BWP is    not the initial BWP:    -   2> if a PDCCH addressed to C-RNTI or CS-RNTI indicating uplink        grant is received for the active BWP of this serving cell:        -   3> if there is no ongoing random access procedure associated            with this Serving Cell:            -   4> start or restart the BWP-InactivityTimer of this                serving cell (i.e. start or restart the                BWP-InactivityTimer associated with active DL BWP of                this serving cell or start the BWP-InactivityTimer of                this serving cell);

For example, UE receives a PDCCH addressed to C-RNTI or CS-RNTIindicating uplink grant. The UL grant is for active UL BWP of servingcell X. If there is no ongoing random access procedure associated withserving cell X, UE (re-)starts BWP-InactivityTimer associated withactive DL BWP of serving cell X. Note that PDCCH indicating this ULgrant may be received on active DL BWP of serving cell X or anotherserving cell Y. In this embodiment, if there are multiple active DL BWPsin a serving cell, operation of start or restart the BWP-InactivityTimeris for the BWP-InactivityTimer associated with active DL BWP linked with(i.e. have same BWP ID as the) UL BWP for which UL grant is received.

In another embodiment of the proposed invention, MAC entity in UEperform the following operation for each activated serving cellconfigured with BWP inactivity timer:

-   1> if a PDCCH addressed to C-RNTI or CS-RNTI indicating uplink grant    is received on or for the active BWP of a serving cell:    -   2> if this serving cell is a SpCell:        -   3> if there is no ongoing random access procedure (no            ongoing random access procedure initiated on this serving            cell or any SCell of the CG associated with SpCell), start            or restart the BWP-InactivityTimer of this Serving Cell            (i.e. start or restart the BWP-InactivityTimer associated            with active DL BWP of this serving cell or start the            BWP-InactivityTimer of this serving cell);    -   2> else        -   3> if there is no ongoing random access procedure initiated            on this serving cell, start or restart the            BWP-InactivityTimer of this Serving Cell (i.e. start or            restart the BWP-InactivityTimer associated with active DL            BWP of this serving cell or start the BWP-InactivityTimer of            this serving cell)

In another embodiment of the proposed invention, MAC entity in UEperform the following operation for each activated serving cellconfigured with BWP inactivity timer:

-   1> if a PDCCH addressed to C-RNTI or CS-RNTI indicating uplink grant    is received on or for the active BWP of a serving cell:    -   2> if this serving cell is a SCell (i.e. secondary cell other        than PSCell):        -   3> if there is no ongoing random access procedure initiated            on this serving cell, start or restart the            BWP-InactivityTimer of this Serving Cell (i.e. start or            restart the BWP-InactivityTimer associated with active DL            BWP of this serving cell or start the BWP-InactivityTimer of            this serving cell);    -   2> else        -   3> if there is no ongoing random access procedure (no            ongoing random access procedure initiated on this serving            cell or any SCell of the CG associated with SpCell), start            or restart the BWP-InactivityTimer of this Serving Cell            (i.e. start or restart the BWP-InactivityTimer associated            with active DL BWP of this serving cell or start the            BWP-InactivityTimer of this serving cell)

In one method of the invention it is proposed to handle Measurement Gapduring Beam Failure Recovery Response Window

The beam failure recovery request procedure is used for indicating tothe serving gNB of a new SSB or CSI-RS when beam failure is detected onthe serving SSB(s)/CSI-RS(s). For beam failure recovery request, UEtransmits the contention free Random Access Preamble. It is to be notedthat Random access preambles and/or PRACH resources can be dedicated forbeam failure recovery request. After transmitting the contention freeRandom Access Preamble for beam failure recovery request, UE start thebfr-ResponseWindow (i.e. RAR window configured in beam failure recoveryconfiguration signaled by gNB to UE) at the start of the first PDCCHoccasion after a fixed duration of X symbols from the end of thepreamble transmission. bfr-ResponseWindow (in units of number of slotsor subframes or TTIs or PDCCH occasions or OFDM symbols) is configuredin system information or in a dedicated RRC signaling. UE monitors thePDCCH of the SpCell for response to beam failure recovery requestidentified by the C-RNTI while bfr-ResponseWindow is running

It is possible that one or more time slots in bfr-ResponseWindow mayoverlap with the measurement gaps. During a measurement gap, UE normallydoes not monitor PDCCH, does not perform the transmission of HARQfeedback and CQI/PMI/RI/CRI, does not report SRS and does not transmitUL-SCH (except for Msg3). We propose if a measurement gap occur duringthe bfr-ResponseWindow, UE prioritizes monitoring the PDCCH of theSpCell for response to beam failure recovery request identified by theC-RNTI instead of skipping the PDCCH monitoring. Beam failure recoveryprocedure is important than performing measurements during themeasurement gaps.

FIG. 12 illustrates UE operation in one embodiment of the proposedinvention to handle measurement gap during Beam Failure RecoveryResponse Window according to an embodiment of the disclosure.

Referring to FIG. 12, in operation 1200, UE receives measurement gapconfiguration from gNB.

In operation 1210, UE performs measurement during measurement gaps.

In operation 1220, if beam failure is detected, UE initiates beamfailure recovery procedure.

In operation 1230, UE transmits beam failure recovery request to gNB.

In operation 1240, UE monitors beam failure recovery response inbfr-ResponseWindow.

In an embodiment, during a measurement gap, the UE (or MAC entity in UE)shall:

-   1> if the bfr-ResponseWindow is running.    -   2> monitor the PDCCH addressed to C-RNTI; UE monitors the PDCCH        of the SpCell for response to beam failure recovery request        identified by the C-RNTI

In an embodiment, during a measurement gap, the MAC entity shall:

-   1> if the ra-ResponseWindow, bfr-ResponseWindow or the    ra-ContentionResolutionTimer is running:    -   2> monitor the PDCCH; (Note: In case of ra-ResponseWindow, UE        monitors for PDCCH addressed to RA-RNTI. In case of        bfr-ResponseWindow, UE monitors for PDCCH addressed to C-RNTI.        In case of ra-ContentionResolutionTimer, UE monitors for PDCCH        addressed to C-RNTI.)-   1> else:    -   2> not monitor the PDCCH.

In operation 1250, in case of measurement gap during bfr-ResponseWindow,UE monitors PDCCH for beam failure recovery response.

In one method of the invention it is proposed to enhance Beam FailureRecovery Procedure

The current procedure for beam failure recovery is defined as follows:The beam failure recovery request procedure is used for indicating tothe serving gNB of a new SSB or CSI-RS when beam failure is detected onthe serving SSB(s)/CSI-RS(s). Beam failure is detected by the lowerlayers and indicated to the MAC entity.

The MAC entity shall:

-   1> if beam failure indication has been received from lower layers:    -   2> start or restart the beamFailureRecoveryTimer;    -   2> increment BFI_COUNTER by 1;    -   2> if BFI_COUNTER>=beamFailureInstanceMaxCount:        -   3> if beamFailureRecoveryConfig is configured for the active            UL BWP:            -   4> start the beamFailureRecoveryTimer, if configured;            -   4> initiate a random access procedure (see 3GPP TS                38.321 subclause 5.1) on the SpCell by applying the                parameters powerRampingStep,                preambleReceivedTargetPower, and preambleTransMax                configured in beamFailureRecoveryConfig.        -   3> else:            -   4> initiate a random access procedure (see 3GPP TS                38.321 subclause 5.1) on the SpCell.-   1> if the beamFailureRecoveryTimer expires; or-   1> if beamFailureDetectionTimer, beamFailureInstanceMaxCount, or any    of the reference signals used for beam failure detection is    reconfigured by upper layers:    -   2> set BFI_COUNTER to 0-   1> if downlink assignment or uplink grant on the PDCCH addressed for    the C-RNTI has been received:    -   2> stop and reset beamFailureRecoveryTimer;    -   2> consider the Beam Failure Recovery Request procedure        successfully completed.

In case contention based random access procedure is used for beamfailure recovery and recovery is successful, beamFailureRecoveryTimerwill continue to run and on expiry it will reset the BFI_COUNTER. As aresult, the subsequent beam failure detection and recovery is affected.

In order to overcome the above issues, the following enhanced procedureis proposed in an embodiment of the proposed invention. The main pointis that upon successful completion of random access procedure initiatedfor beam failure recovery, beamFailureRecoveryTimer is stopped if thebeamFailureRecoveryTimer is configured by gNB in RRC signaling

-   1> if beam failure indication has been received from lower layers    (i.e. Physical layer):    -   2> start or restart the beamFailureRecoveryTimer;    -   2> increment BFI_COUNTER by 1;    -   2> if BFI_COUNTER>=beamFailureInstanceMaxCount:        -   3> if beamFailureRecoveryConfig is configured for the active            UL BWP:            -   4> start the beamFailureRecoveryTimer, if configured;            -   4> initiate a random access procedure (see subclause                5.1) on the SpCell by applying the parameters                powerRampingStep, preambleReceivedTargetPower, and                preambleTransMax configured in                beamFailureRecoveryConfig.        -   3> else:            -   4> initiate a random access procedure (e.g. on SpCell);-   1> if the beamFailureRecoveryTimer expires; or-   1> if beamFailureDetectionTimer, beamFailureInstanceMaxCount, or any    of the reference signals used for beam failure detection is    reconfigured by upper layers:    -   2> set BFI_COUNTER to 0;-   1> if the random access procedure initiated for beam failure    recovery is successfully completed:    -   3> stop the beamFailureRecoveryTimer, if configured;    -   3> set BFI_COUNTER to 0;    -   3> consider the Beam Failure Recovery Request procedure        successfully completed;

In an embodiment, if contention free random access preamble and/or PRACHoccasion is used for transmitting PRACH preamble and if PDCCH inrecovery search space addressed to C-RNTI is received whileRandomAccessResponseWindow is running, random access procedure initiatedfor beam failure recovery is considered successfully completed.Otherwise if random access preamble was selected amongst the contentionbased random access preambles for transmitting PRACH preamble and ifPDCCH addressed to C-RNTI is received while ra-ContentionResolutionTimeris running, random access procedure initiated for beam failure recoveryis considered successfully completed. As explained earlier, if randomaccess procedure is initiated by UE is not for beam failure recovery, ifrandom access preamble was selected amongst the contention based randomaccess preambles for transmitting PRACH preamble and if PDCCH addressedto C-RNTI indicating UL assignment for new transmission is receivedwhile ra-ContentionResolutionTimer is running, random access procedureis considered successfully completed.

In another embodiment, if contention free random access preamble and/orPRACH occasion is used for transmitting PRACH preamble and if PDCCH inrecovery search space addressed to C-RNTI is received whileRandomAccessResponseWindow is running, random access procedure initiatedfor beam failure recovery is considered successfully completed.Otherwise if random access preamble was selected amongst the contentionbased random access preambles for transmitting PRACH preamble and ifPDCCH addressed to C-RNTI indicating a DL or UL assignment is receivedwhile ra-ContentionResolutionTimer is running, random access procedureinitiated for beam failure recovery is considered successfullycompleted. As explained earlier, if random access procedure is initiatedby UE is not for beam failure recovery, if random access preamble wasselected amongst the contention based random access preambles fortransmitting PRACH preamble and if PDCCH addressed to C-RNTI indicatingUL assignment for new transmission is received whilera-ContentionResolutionTimer is running, random access procedure isconsidered successfully completed.

In one method of the invention it is proposed to handle Temporary C-RNTIfor Contention Based Random Access (CBRA) Procedure.

CBRA Procedure includes the following 4 steps:

1. UE transmits random access preamble to gNB. The random accesspreamble is selected from the contention based random access preambles.2. GNB transmits the RAR on PDSCH addressed to RA-RNTI. RA-RNTIidentifies the time-frequency slot in which RA preamble was detected bygNB. RAR conveys RA preamble identifier, Timing alignment information,Temporary C-RNTI and UL grant for message 3. RAR may also include backoff indicator to instruct UE to back off for period of time beforeretrying RA attempt. RAR is transmitted in RAR window. RAR window sizeis configurable.3. UE transmits CCCH SDU in UL grant received in RAR. It is used totransmit message such as RRC Connection Request, RRC ConnectionRe-establishment request, RRC handover confirm, scheduling request, SIrequest etc. This is commonly referred as MSG3. After sending Msg3, UEwaits for Msg 4. UE also starts contention resolution timer.4. If UE receives PDCCH addressed to TEMPORARY_C-RNTI and if the MAC PDUis successfully decoded:

-   1> if the MAC PDU contains a UE Contention Resolution Identity MAC    CE; and-   1> if the UE Contention Resolution Identity in the MAC CE matches    the CCCH SDU transmitted in Msg3:    -   2> consider this Contention Resolution successful;    -   2> set the C-RNTI to the value of the TEMPORARY_C-RNTI;

In the current procedure, after the contention resolution is successful,UE always promote TEMPORARY_C-RNTI to C-RNTI. In the invention wepropose that depending on type of message included in CCCH SDU, UEdecide whether to promote TEMPORARY_C-RNTI to C-RNTI or not. If thecontention resolution is successful and If CCCH SDU does not includes SIrequest or if SI request was not transmitted in Msg3 or if the randomaccess procedure was not triggered for SI request, UE promotesTEMPORARY_C-RNTI to C-RNTI. Otherwise UE does not promoteTEMPORARY_C-RNTI to C-RNTI. It only indicates reception of SI requestack to upper layers.

-   1> After transmitting the CCCH SDU in Msg3, if UE receives PDCCH    addressed to TEMPORARY_C-RNTI and if the MAC PDU is successfully    decoded:    -   2> if the MAC PDU contains a UE Contention Resolution Identity        MAC CE; and    -   2> if the UE Contention Resolution Identity in the MAC CE        matches the CCCH SDU transmitted in Msg3:        -   3> consider this Contention Resolution successful;        -   3> if SI request was not transmitted in Msg3:            -   4> set the C-RNTI to the value of the TEMPORARY_C-RNTI;        -   3> else if SI request was transmitted in Msg3:            -   4> Inform upper layer that SI ack is received

In one method of the invention it is proposed to handle PDCCH IndicatingBWP switching.

<Method 1>

In the existing design, UE always switch BWP upon receiving BWPswitching command. This may interrupt the ongoing random accessprocedure and hence delays the completion of random access procedure.The UE operation in one embodiment of the proposed invention is asfollows:

UE receives from gNB a PDCCH or RRC reconfiguration message for BWPswitching for a serving cell. UE checks whether there is any ongoingrandom access procedure associated with this serving cell.

If there is no ongoing random access procedure associated with thisserving cell

-   -   Perform BWP switching to a BWP indicated by the PDCCH or RRC        reconfiguration message.

Else If there is ongoing random access procedure associated with thisserving cell:

-   -   Option 1: Perform BWP switching to a BWP indicated by the PDCCH        or RRC reconfiguration message.    -   Option 2: Ignore the PDCCH for BWP switching.    -   If the MAC entity decides to perform BWP switching, the MAC        entity shall stop the ongoing Random Access procedure and        initiate a Random Access procedure on the new activated BWP. If        the MAC decides to ignore the PDCCH for BWP switching, the MAC        entity shall continue with the ongoing Random Access procedure        on the active BWP.

A random access procedure is associated with serving cell if the PRACHpreamble was transmitted on the serving cell by UE and/or UE receivesRAR on the serving cell. For example, if random access procedure isinitiated on SCell (other than PSCell), UE transmits PRACH preamble onScell and receives RAR on SpCell. So, in this case, random accessprocedure is associated with SCell as well as SpCell. For example, ifrandom access procedure is initiated on SpCell, UE transmits PRACHpreamble on SpCell and receives RAR on SpCell. So, in this case, randomaccess procedure is associated with SpCell.

The UE operation in another embodiment of the proposed invention is asfollows:

UE receives a PDCCH or RRC reconfiguration message for BWP switching fora serving cell.

If this serving cell is SpCell:

-   -   if there is no ongoing random access procedure (no ongoing        random access procedure initiated on this serving cell or any        SCell of the CG associated with SpCell),        -   perform BWP switching to a BWP indicated by the PDCCH or RRC            reconfiguration message;    -   else        -   Option 1: Perform BWP switching to a BWP indicated by the            PDCCH or RRC reconfiguration message.        -   Option 2: Ignore the PDCCH for BWP switching.    -   If the MAC entity decides to perform BWP switching, the MAC        entity shall stop the ongoing random access procedure and        initiate a random access procedure on the new activated BWP. If        the MAC decides to ignore the PDCCH for BWP switching, the MAC        entity shall continue with the ongoing random access procedure        on the serving cell.    -   else if this serving cell is not SpCell:    -   if there is no ongoing random access procedure initiated on this        serving cell,        -   perform BWP Switching to a BWP indicated by the PDCCH or RRC            reconfiguration message    -   else        -   Option 1: Perform BWP switching to a BWP indicated by the            PDCCH or RRC reconfiguration message.        -   Option 2: Ignore the PDCCH or RRC reconfiguration message            for BWP switching.        -   If the MAC entity decides to perform BWP switching, the MAC            entity shall stop the ongoing random access procedure and            initiate a random access procedure on the new activated BWP.            If the MAC decides to ignore the PDCCH or RRC            reconfiguration message for BWP switching, the MAC entity            shall continue with the ongoing random access procedure on            the serving cell.

<Method 2>

UE receives from gNB a PDCCH or RRC reconfiguration message for BWPswitching for a serving cell.

-   -   If this serving cell is a SCell and the duplexing scheme on this        serving cell is TDD and the received PDCCH or RRC        reconfiguration message for BWP switching is for switching the        active DL BWP, MAC entity performs BWP Switching to a BWP        indicated by the PDCCH or RRC reconfiguration message.    -   If this serving cell is a SCell and the duplexing scheme on this        serving cell is TDD and the received PDCCH or RRC        reconfiguration message for BWP switching is for switching the        active UL BWP:        -   if there is ongoing random access procedure associated with            this serving cell:            -   Option 1: Perform BWP switching to a BWP indicated by                the PDCCH or RRC reconfiguration message.            -   Option 2: Ignore the PDCCH for BWP switching.            -   If the MAC entity decides to perform BWP switching, the                MAC entity shall stop the ongoing random access                procedure and initiate a random access procedure on the                new activated BWP. If the MAC decides to ignore the                PDCCH for BWP switching, the MAC entity shall continue                with the ongoing random access procedure on the serving                cell.        -   Else            -   Perform BWP switching to a BWP indicated by the PDCCH or                RRC reconfiguration message.    -   If this serving cell is a SpCell and the duplexing scheme on        this serving cell is TDD and the received PDCCH or RRC        reconfiguration message for BWP switching is for switching the        active DL BWP:        -   if there is ongoing random access procedure associated with            this serving cell:            -   Option 1: Perform BWP switching to a BWP indicated by                the PDCCH or RRC reconfiguration message.            -   Option 2: Ignore the PDCCH for BWP switching.            -   If the MAC entity decides to perform BWP switching, the                MAC entity shall stop the ongoing random access                procedure and initiate a random access procedure on the                new activated BWP. If the MAC decides to ignore the                PDCCH for BWP switching, the MAC entity shall continue                with the ongoing random access procedure on the serving                cell.    -   If this serving cell is a SpCell and the duplexing scheme on        this serving cell is TDD and the received PDCCH or RRC        reconfiguration message for BWP switching is for switching the        active UL BWP:        -   if there is ongoing random access procedure initiated (i.e.            RA preamble is transmitted) on this serving cell:            -   Option 1: Perform BWP switching to a BWP indicated by                the PDCCH or RRC reconfiguration message.            -   Option 2: Ignore the PDCCH for BWP switching.            -   If the MAC entity decides to perform BWP switching, the                MAC entity shall stop the ongoing random access                procedure and initiate a random access procedure on the                new activated BWP. If the MAC decides to ignore the                PDCCH for BWP switching, the MAC entity shall continue                with the ongoing random access procedure on the serving                cell.        -   Else            -   Perform BWP switching to a BWP indicated by the PDCCH or                RRC reconfiguration message.

The advantage of method 2 is that for TDD cells, the BWP switchingcommand can be processed in certain cases even if random accessprocedure is ongoing without stopping the ongoing random accessprocedure.

FIG. 13 illustrates a UE apparatus according to an embodiment to thedisclosure.

Referring to FIG. 13, the UE (1300) includes a transceiver (1310), acontroller (1320) and a memory (1330). Alternatively, the transceivermay be implemented as a transmitter and a receiver, and each componentmay be implemented through one or more processors.

The transceiver (1310) is configured to receive and transmit signal,data and control information associated with BWP configuration, handlingBWP-InactivityTimer, random access procedure or beam failure management.

The transceiver (1310) is configured to transmit random access preambleand receive random access response and scheduled transmission.

The controller (1320) is configured to control operation associated withBWP configuration, handling BWP-InactivityTimer, random access procedureor beam failure management above-described embodiments of thedisclosure.

The controller (1320) is configured to the transceiver to receive, froma base station, first information of a first timer of a bandwidth partinactivity associated with a bandwidth part of a primary cell (PCell)and second information of a second timer of a bandwidth part inactivityassociated with a bandwidth part of a secondary cell (SCell); identifythat a random access procedure is initiated on the PCell or the SCell;stop the first timer, if running, in response to identifying that therandom access procedure is initiated on the PCell; and stop the firsttimer and the second timer, if running, in response to identifying thatthe random access procedure is initiated on the SCell.

The SCell and the PCell are associated with the random access procedure.

The random access procedure is performed based on an active uplink(UL)bandwidth part (BWP) of the PCell or the SCell.

The random access procedure is performed based on an active downlink(DL) bandwidth part (BWP) of the PCell.

The controller (1320) is configured to control the transceiver toreceive, from a base station, first information of a timer associatedwith bandwidth part (BWP) inactivity; control the transceiver toreceive, from the base station, physical downlink control channel(PDCCH) on an active BWP associated with a serving cell; identifywhether there is ongoing random access procedure associated with theserving cell; and start or re-start the timer in response to identifyingthat there is no ongoing random access procedure associated with theserving cell.

The active BWP is different from either a default downlink(DL) bandwidthpart (BWP) or an initial BWP.

The PDCCH indicates a downlink assignment or an uplink grant.

The PDCCH is received on the active BWP or received for the active BWP.

The controller (1320) is configured to control the transceiver totransmit, to a base station, a random access preamble for initiating arandom access procedure and receive, from the base station, a randomaccess response and transmit, to the base station, a first message forrequesting system information (SI) and receive, from the base station,physical downlink control channel (PDCCH) associated with a temporarycell radio network temporary identifier (TEMPORARY C-RNTI); identifywhether a contention resolution is successful; identify whether a randomaccess procedure is initiated for requesting the SI; and indicate areception of an acknowledgement for requesting the SI to upper layer inresponse to identifying that the contention resolution is successful andthe random access procedure is initiated for requesting the SI.

The processor is further configured to set a cell radio networktemporary identifier (C-RNTI) to a value of the TEMPORARY C-RNTI inresponse to identifying that the contention resolution is successful andthe random access procedure is not initiated for requesting the SI.

The random access procedure is associated with contention-based randomaccess.

A contention resolution is identified successful in response toidentifying that UE Contention Resolution Identity in a MAC CE receivedin a MAC PDU matches a CCCH SDU transmitted in the first message.

The controller (1320) is configured to control the transceiver toreceive, from a base station, physical downlink control channel (PDCCH)for bandwidth part (BWP) switching of a serving cell; identify whetherthere is ongoing random access procedure associated with the servingcell; and perform BWP switching based on the PDCCH in response toidentifying that there is no ongoing random access procedure.

The BWP switching is performed based on the PDCCH in response toidentifying that there is ongoing random access procedure.

The ongoing random access procedure is stopped in response toidentifying that the BWP switching is performed.

The PDCCH for BWP switching is ignored in response to identifying thatthere is ongoing random access procedure.

The controller (1320) is configured to control the transceiver toreceive first information of a timer associated with a beam failurerecovery and second information of maximum count value associated withbeam failure instance; identify a number of beam failure instances;identify whether the number of beam failure instances is greater orequal to the second information; start the timer associated with thebeam failure recovery in response to identifying that the number of beamfailure instances is greater or equal to the second information; controlthe transceiver to transmit a contention-free random access preamble forinitiating a random access procedure for a beam failure recoveryrequest; control the transceiver to receive physical downlink controlchannel (PDCCH) associated with a cell radio network temporaryidentifier (C-RNTI) of the UE; identify whether the random accessprocedure is completed successfully; and stop the timer in response toidentifying that the random access procedure is completed successfully.

The first information and the second information is received by higherlayer signaling.

The number of beam failure instances is set to zero in response toidentifying that the random access procedure is completed successfully.

The beam failure recovery is identified completed in response toidentifying that the random access procedure is completed successfully.

The memory (1330) is configured to store information associated with BWPconfiguration, handling BWP-InactivityTimer, random access procedure orbeam failure management above-described embodiments of the disclosure.

FIG. 14 illustrates a base station apparatus according to an embodimentof the disclosure.

Referring to FIG. 14, the base station (1400) includes a transceiver(1410), a controller (1420) and a memory (1430). Alternatively, thetransceiver may be implemented as a transmitter and a receiver, and eachcomponent may be implemented through one or more processors.

Referring to FIG. 14, the transceiver (1410) is configured to receiveand transmit signal, data and control information associated with BWPconfiguration, handling BWP-InactivityTimer, random access procedure orbeam failure management.

The transceiver (1410) is configured to receive random access preambleand transmit random access response and scheduled transmission.

The controller (1420) is configured to control operation associated withBWP configuration, handling BWP-InactivityTimer, random access procedureor beam failure management above-described embodiments of thedisclosure.

The controller (1420) is configured to control the transceiver to:transmit, to a user equipment (UE), first information of a first timerof a bandwidth part inactivity associated with a bandwidth part of aprimary cell (PCell) and second information of a second timer of abandwidth part inactivity associated with a bandwidth part of asecondary cell (SCell); receive, from the UE, a first message associatedwith a random access procedure on the PCell or the SCell; and transmit,to the UE, a second message associated with the random access procedureon the PCell, wherein the first timer, if running, is stopped inresponse to identifying that the random access procedure is initiated onthe PCell, and wherein the first timer and the second timer, if running,are stopped in response to identifying that the random access procedureis initiated on the SCell.

The first message including physical random access channel (PRACH)preamble is received on an active uplink(UL) bandwidth part (BWP) of thePCell or the SCell.

The SCell and the PCell are associated with the random access procedure.

The second message including random access response (RAR) is transmittedon an active downlink (DL) bandwidth part (BWP) of the PCell.

The controller (1420) is configured to control the transceiver to:transmit, to a user equipment(UE), first information of a timerassociated with bandwidth part (BWP) inactivity; and transmit, to theUE, physical downlink control channel (PDCCH) on an active BWPassociated with a serving cell, wherein the timer is started orre-started in response to identifying that there is no ongoing randomaccess procedure associated with the serving cell.

The active BWP is different from either a default downlink (DL)bandwidth part (BWP) or an initial BWP.

The PDCCH indicates a downlink assignment or an uplink grant.

The PDCCH is transmitted on the active BWP or transmitted for the activeBWP.

The controller (1420) is configured to control the transceiver toreceive, from a user equipment (UE), a random access preamble forinitiating a random access procedure and transmit, to the UE, a randomaccess response and receive, from the UE, a first message for requestingsystem information (SI) and transmit, to the UE, physical downlinkcontrol channel (PDCCH) associated with a temporary cell radio networktemporary identifier (TEMPORARY C-RNTI) and transmit, to the UE, anacknowledgement for requesting the SI in response to identifying that acontention resolution is successful and a random access procedure isinitiated for requesting the SI.

A cell radio network temporary identifier (C-RNTI) is set to a value ofthe TEMPORARY C-RNTI in response to identifying that the contentionresolution is successful and the random access procedure is notinitiated for requesting the SI.

The random access procedure is associated with contention-based randomaccess.

A contention resolution is identified successful in response toidentifying that UE Contention Resolution Identity in a MAC CEtransmitted in a MAC PDU matches a CCCH SDU received in the firstmessage.

The controller (1420) is configured to control the transceiver to:transmit, to a user equipment(UE), bandwidth part (BWP) configurationinformation including information associated with an active bandwidthpart (BWP) of a serving cell; and transmit, to the UE, physical downlinkcontrol channel (PDCCH) for bandwidth part (BWP) switching of theserving cell, wherein the BWP switching is performed based on the PDCCHin response to identifying that there is no ongoing random accessprocedure associated with the serving cell.

The BWP switching is performed based on the PDCCH in response toidentifying that there is ongoing random access procedure associatedwith the serving cell.

The ongoing random access procedure is stopped in response toidentifying that the BWP switching is performed.

The PDCCH for BWP switching is ignored in response to identifying thatthere is ongoing random access procedure associated with the servingcell.

The controller (1420) is configured to control the transceiver to:transmit, to a user equipment (UE), first information of a timerassociated with a beam failure recovery and second information ofmaximum count value associated with beam failure instance; receive, fromUE, a contention-free random access preamble for initiating a randomaccess procedure for a beam failure recovery request; and transmit, tothe UE, physical downlink control channel (PDCCH) associated with a cellradio network temporary identifier (C-RNTI) of the UE, wherein the timeris started in response to identifying that a number of beam failureinstances is greater or equal to the second information and the timer isstopped in response to identifying that the random access procedure iscompleted successfully.

The first information and the second information is transmitted byhigher layer signaling.

The number of beam failure instances is set to zero in response toidentifying that the random access procedure is completed successfully.

The beam failure recovery is identified completed in response toidentifying that the random access procedure is completed successfully.

The memory (1430) is configured to store information associated with BWPconfiguration, handling BWP-InactivityTimer, random access procedure orbeam failure management above-described embodiments of the disclosure.

The above-described embodiments of the disclosure and the accompanyingdrawings have been provided only as specific examples in order to assistin understanding the disclosure and do not limit the scope of thedisclosure. Accordingly, those skilled in the art to which thedisclosure pertains will understand that other change examples based onthe technical idea of the disclosure may be made without departing fromthe scope of the disclosure.

While the disclosure has been shown and described with reference tovarious embodiments thereof, it will be understood by those skilled inthe art that various changes in form and details may be made thereinwithout departing from the spirit and scope of the disclosure as definedby the appended claims and their equivalents.

The operations performed by the module, programming module, or any othercomponent according to various embodiments may be executed sequentially,in parallel, repeatedly, or by a heuristic method. Additionally, someoperations may be executed in different orders or omitted, or any otheroperation may be added.

The methods of the embodiments illustrated in FIGS. 1 to 12 can includea combination of methods from more than one illustration. For example,FIGS. 1 to 12 illustrate operations related to a random access procedureand based on various embodiments, the methods can include a combinationof methods from more than one illustration.

What is claimed is:
 1. A method of a user equipment (UE), the methodcomprising: receiving first information of a timer associated with abeam failure recovery and second information of maximum count valueassociated with beam failure instance; identifying a number of beamfailure instances; identifying whether the number of beam failureinstances is greater or equal to the second information; starting thetimer associated with the beam failure recovery in response toidentifying that the number of beam failure instances is greater orequal to the second information; transmitting a contention-free randomaccess preamble for initiating a random access procedure for a beamfailure recovery request; receiving physical downlink control channel(PDCCH) associated with a cell radio network temporary identifier(C-RNTI) of the UE; identifying whether the random access procedure iscompleted successfully; and stopping the timer in response toidentifying that the random access procedure is completed successfully.2. The method of claim 1, wherein the first information and the secondinformation is received by higher layer signaling.
 3. The method ofclaim 1, wherein the number of beam failure instances is set to zero inresponse to identifying that the random access procedure is completedsuccessfully.
 4. The method of claim 1, wherein the beam failurerecovery is identified completed in response to identifying that therandom access procedure is completed successfully.
 5. A method of a basestation, the method comprising: transmitting, to a user equipment (UE),first information of a timer associated with a beam failure recovery andsecond information of maximum count value associated with beam failureinstance; receiving, from UE, a contention-free random access preamblefor initiating a random access procedure for a beam failure recoveryrequest; and transmitting, to the UE, physical downlink control channel(PDCCH) associated with a cell radio network temporary identifier(C-RNTI) of the UE, wherein the timer is started in response toidentifying that a number of beam failure instances is greater or equalto the second information and the timer is stopped in response toidentifying that the random access procedure is completed successfully.6. The method of claim 5, wherein the first information and the secondinformation is transmitted by higher layer signaling
 7. The method ofclaim 5, wherein the number of beam failure instances is set to zero inresponse to identifying that the random access procedure is completedsuccessfully.
 8. The method of claim 5, wherein the beam failurerecovery is identified completed in response to identifying that therandom access procedure is completed successfully.
 9. A user equipment(UE) in a wireless communication system, the UE comprising: atransceiver; and at least one processor coupled to the transceiver, theprocessor configured to: control the transceiver to receive firstinformation of a timer associated with a beam failure recovery andsecond information of maximum count value associated with beam failureinstance; identify a number of beam failure instances; identify whetherthe number of beam failure instances is greater or equal to the secondinformation; start the timer associated with the beam failure recoveryin response to identifying that the number of beam failure instances isgreater or equal to the second information; control the transceiver totransmit a contention-free random access preamble for initiating arandom access procedure for a beam failure recovery request; control thetransceiver to receive physical downlink control channel (PDCCH)associated with a cell radio network temporary identifier (C-RNTI) ofthe UE; identify whether the random access procedure is completedsuccessfully; and stop the timer in response to identifying that therandom access procedure is completed successfully.
 10. The UE of claim9, wherein the first information and the second information is receivedby higher layer signaling.
 11. The UE of claim 9, wherein the number ofbeam failure instances is set to zero in response to identifying thatthe random access procedure is completed successfully.
 12. The UE ofclaim 9, wherein the beam failure recovery is identified completed inresponse to identifying that the random access procedure is completedsuccessfully.
 13. A base station in a wireless communication system, thebase station comprising: a transceiver; and at least one processorcoupled to the transceiver, the processor configured to control thetransceiver to: transmit, to a user equipment (UE), first information ofa timer associated with a beam failure recovery and second informationof maximum count value associated with beam failure instance; receive,from UE, a contention-free random access preamble for initiating arandom access procedure for a beam failure recovery request; andtransmit, to the UE, physical downlink control channel (PDCCH)associated with a cell radio network temporary identifier (C-RNTI) ofthe UE, wherein the timer is started in response to identifying that anumber of beam failure instances is greater or equal to the secondinformation and the timer is stopped in response to identifying that therandom access procedure is completed successfully.
 14. The base stationof claim 13, wherein the number of beam failure instances is set to zeroin response to identifying that the random access procedure is completedsuccessfully.
 15. The base station of claim 13, wherein the beam failurerecovery is identified completed in response to identifying that therandom access procedure is completed successfully.